It was two weeks before Christmas, 1992. Visions of sparkling trees and holiday spirit danced in their heads as they drove home from a family gathering. Suddenly there was a loud, deadening crunch and flames shot up in front of the shocked driver and passengers. A '90 Ford Tempo had crossed the center line, hitting them head on at a 100-mph closing speed. The left front of their '92 Buick LeSabre was a tangled mass of steel, the hood smashed and curled back. A deflated air bag lay withered across the steering wheel.

The Buick's driver heard nothing when the air bag exploded. He began coughing from the chemicals, and his left thumb throbbed. His front-seat passenger had no air bag and a stabbing pain raged through her right shoulder where the shoulder belt held her fast. Both were able to quickly get out of the car, and pull out their two children sleeping in the back seat.

The Tempo driver, held in by his seat belt and a collapsed front end, lay pinned in terror as rescue units worked to remove him. "I didn't think anyone could have survived in either car," a witness told police.

Final injury report: Buick driver -- sprained thumb and miscellaneous bruises. Buick passenger -- broken collarbone, collapsed lung and sprained foot. Buick kids -- simple bruises from seat belts. Tempo driver -- air-lifted to the University of Michigan hospital with internal injuries and a broken leg that took several surgeries to repair.

It was an accident meant for the statistics books. The Tempo weighs in at about 2,500 lbs. ( 1, 140 kg), LeSabre at almost 3,400 lbs. (1,545 kg). The Buick had one air bag, Tempo none. The children basically escaped injury unhurt. Big car vs. little car. Belt vs. air bag. How much safety is enough?

Webster defines safe as free from harm or risk; secure from threat of danger, harm or loss. That's a myth when it comes to driving. There's always a risk behind the wheel. Would radar have stopped those two cars from hitting head-on? Would night-vision have made a difference? The truth is that people often can't react fast enough, or aren't trained well enough, to take advantage of the safety systems they already have.

That's one reason for the so-called federal "passive restraint" mandate: air bags are nobrainers. If the car crashes, they're going to inflate and, God willing, save your life. But they're more effective if people buckle up.

Antilock braking systems (ABS) also are engineered to do their job -- keeping steering control during panic-braking under slippery conditions -- with not much more driver input than jamming the brake pedal. But it helps to know a tad more than that about ABS to use the systems effectively. Some experts swear by ABS, which is fast-becoming standard equipment or at least available in every U.S. car and truck (see table p.35). Others say there's little or no safety advantage. And a sizable cross-section believes drivers simply don't know how to use ABS properly.

After decades of bitterly opposing tougher federal safety standards, automakers these days are zealously ballyhooing safety features as a potent marketing strategy.

"Safety still sells cars," says Ronald S. Zarowitz, Chrysler Corp.'s manager-safety programs. But he underscores there's a point at which adding more features can produce diminishing returns -- and not just to the bottom line. "The only big opportunity is the driver. Driver behavior is the single most effective potential for increased safety. We have drunk driving down and we're improving seat belt usage; usage is around two-thirds now, but to have one of three not wearing a seat belt is absolutely unacceptable.

"We won't stop moving forward on safety, but that's not to say that the best opportunity is still in educating people," he adds.

Adding more safety features brings up a multitude of debatable questions: How much more do buyers want? How much more will they pay for? How much more will they demand without a substantial boost in price? How much more will government mandated safety features add to the cost of the vehicle? If automakers don't continue to enhance safety, how might this play out on the litigation side? And even if they do add more, is there a risk of still more trips to court questioning whether the safety items performed properly?

Regardless of the answers, unless there is a miracle in productivity increases and supplier cost-cutting, more dollars will be added to stickers for safety features.

How much? That's difficult to say. "Safety is integrated into so many components and systems that you can't quantify it," says Frank Laux, manager-safety standards, General Motors Corp. North American Operations Safety Center.

Generally speaking, the cost of such major items as air bags and ABS have been trending down as volume has soared. A decade ago when ABS was just catching on in the U.S. as optional equipment, the price was around $1,500. Now it's about one-third of that, and still dropping.

"The automakers are being very cost-conscious when they add more safety systems," suggests K.D. Holmgren, president-Automotive Safety Products Group, Morton International Inc. "The industry has done a lot to make cars safer, but there's a balancing act with what people will pay for. It's obvious safety sells; I'd much prefer to have a car with front and side protection for myself and the people riding with me."

The automakers already are a little nervous about car prices. The average cost of a car now runs just over $20,000, big bucks indeed in a society where the mean individual income is about $30,000. And those car prices are up nearly $9,000 in just the last decade.

"The government's own estimates are that mandated safety items between now and 1999 will add $600 to $1,000 to the price of a light truck," says Sherman Henson, manager of advanced safety for Ford Motor Co. "The figure's about $650 for cars." Much of that disparity relates to the fact that lighttruck regulations are starting to catch up with longstanding passenger-car mandates from which trucks had been exempt.

Current standards established by the National Highway Traffic Safety Administration (NHTSA) add only $700 to the cost of a new car, maintains Ricardo Martinez, NHTSA's new administrator. "We expect a given regulation to save a certain number of lives, then we use our database to track that outcome. The benefits of NHTSA's vehicle programs exceed their costs by 5 to 1," he calculates.

Although more passenger-car regulations are coming, the added costs are expected to be small compared to prior mandates. The focus now shifts to trucks, which accounted for 41.9% of total U.S. light-vehicle sales in 1994 -- most of the growth coming in the "personal" market where trucks are displacing cars as family vehicles.

As Ford's Mr. Henson emphasizies, big costs will go into trucks over the next few years as they add more safety features mandated by NHTSA and/or dictated by the competitive marketplace. Several light-truck models already meet the '97 side-impact standard and many are already equipped with dual air bags to gain a marketing edge.

Pickups adopted relatively simple mechanical antilock braking early on to keep their rear-ends from spinning out during hard braking, but as they take on more and more safety items the design challenge becomes especially tough because they're used in such a wide variety of conditions.

"The engineer or designer doesn't know whether on any given day they'll be heavily loaded, lightly loaded or unloaded -- or all of those things," says one safety engineer. "Pickups, for example, are designed for a variety of purposes. People buy them for that very reason. You don't expect a Corvette or Cadillac to handle the same, why expect a Suzuki Samurai to handle like a Lincoln?"

NHTSA has mandated dual air bags in light trucks including sport/utility vehicles (SUVs) in 1999. Side-impact protection must be added by the 1997 model year, the same as cars. However, many light trucks already sport these features, now that safety has captured buyers' attention.

"In the past, the thinking in Washington was 'If it's good for cars it must be good for trucks,"' says Ford's Mr. Henson. "But if you look at trucks, they're different. They are involved in different kinds of accidents. We found that side-door beams have little or no effectiveness for trucks. There are people in Congress putting pressure for cars and trucks to have the same safety items. In some instances there is no benefit for it."

A recent study by the Insurance Institute for Highway Safety (IIHS) gives a slightly different perspective. It lists the best and the worst vehicles to be riding in if there's a crash. One thing that stands out: all except two of the 12 vehicles named as the "best" have air bags and seat belts. Ten of the 12 are large or midsize cars or minivans, and none is a pickup or SUV.

Of the 11 rated "worst," nine have belts only, four are pickups and one is a SUV. The study is based on vehicles with the highest death rates during 1989-1993.

So what's the best vehicle, you ask? The IIHS says it's the Volvo 240 4-door. No one died in a 240 during the four-year test period. The worst? The Chevrolet Corvette. The Institute is quick to point out that very different kinds of people drive those two vehicles. That, combined with other variables such as speed and accident configurations, mean that it is impossible to determine which vehicle is the safest," concedes IIHS President Brian O'Neill.

"We tell consumers to buy the largest car you can afford. That's the first and most effective safety measure -- having more space around you, a bigger crush zone," says an official at the American Automobile Manufacturers Assn. "Second, buy a vehicle with dual air bags."

Despite all the sophisticated new technology, seat belts still are considered the first -- and best -- line of defense. Take for example, ejections. Of those thrown from the vehicle, 95% are not belted, says NHTSA.

One prime example is the single rear tailgate latch on the pre-'96 Chrysler minivans. NHTSA is investigating claims that the latch gives way in certain accidents. There have been 51 crashes causing 25 deaths, 50 injuries and 74 ejections. Most of those flung from the vehicle were not buckled, although how they exited through the rear door undoubtedly keeps accident reconstructionists gainfully occupied.

Archrival Ford, meanwhile, quietly makes sure everyone knows its Windstar minivan has a double tailgate latch.

Even coupled with air bags, seat belts still provide the most protection against serious injury, an estimated 30% to 35%, and IIHS studies show air bags add another 10% to 15% improvement in safety. One thing's for sure with air bags: One is good, two are better. Driver deaths in frontal crashes are about 24% lower if there's an air bag, compared with cars equipped only with a belt.

In all kinds of accidents, there are 16% fewer deaths in cars equipped with bags and belts (if the belts are used), says the IIHS. The agency also suggests that air bags in large cars are best. In front and angle crashes there are 35% fewer deaths in large cars with bags and belts; 17% less in similarly equipped midsize cars, and 26% fewer in small cars.

Adding dual air bags obviously reduces chances of death and serious injury. They are standard on most 1995-model few cars and passenger vans, and driver-side air bags are standard on most SUVs and pickups. Side air bags, which may be a wave of the future, are currently available on only one model: Volvo's '95 850.

More air bags are coming. At last month's North American International Auto Show in Detroit, Acura unveiled its CL-X concept car -- said to be very close to a model it actually intends to build in Ohio -- featuring four air bags, two in front and two behind the front seats to protect rear passengers. Buick's concept XP2000, built to display a ton of advanced technology, has eight air bags.

Mercedes-Benz AG takes a big step beyond everyone else with the "X-bag" research exhibit at the NAIAS.

It has seven different air bag systems that deploy, based on the type of accident. There are driver and passenger air bags, knee bags, side bags, a center bag, B-pillar roof bags, head-restraint bags, rear bags, rear side bags and rear center bags. "The X-bag research car demonstrates some of the possibilities for reducing the remaining risk to occupants," Mercedes says. "In general, advancements in future passive restraints will take the form of refinements to integrated vehicle systems and body structure."

"We're not convinced it (multiple air bags) represent value to the customer," says Ford's Mr. Henson. "You look at the weight and space and the cost of a side air bag and then you ask what else that money could buy." For example, would it be better to use it to make stronger structures or add more cushioning in the door, he asks?. "We're not going to jump on the bandwagon on side air bags," he says.

As for rear bags: "I just don't think that when you get away from the front seat there's that much benefit," he says.

One thing is for sure, though: Safety systems such as air bags still are not cheap, and they can be very expensive to repair. Most air bags add between $400 or $500 to the cost of the car. But, as Morton's Mr. Holmgren points out, in the late-'80s driver-side air bags were listed as $800 options on luxury cars. "There has been a 40% or 50% reduction since the early days," he reckons.

Some designs that make air bags less expensive to assemble actually may make them more expensive to repair. Insurance industry sources say the least expensive replacement steering wheel hub air bag module (Chrysler's) costs about $365. The most expensive -- on an unspecified Toyota Motor Corp. vehicle -- costs $1,250.

Some very expensive luxury cars, such as Mercedes and BMW models, aren't totalled in severe accidents and well worth repairing. These automakers already are implementing systems that will deploy bags and pyrotechnic seat belt tensioners, and other devices, only when absolutely necessary, and the passenger bag won't inflate at all if the seat isn't occupied. The aim is to save repair dollars.

That's great news for the insurance industry, but it's not the only concern. One insurance industry source wonders out loud about how much money air bags can really save insurers in terms of reducing injuries and deaths.

"Preliminary data says the death rate is down, but before, insurers just paid off a death penalty," he says. He worries that in some cases where there is a very severe accident, air bags may save lives but leave the victims permanently incapacitated and require very expensive life-long care and therapy, thus actually raising costs that could affect rates. It comes down to tough societal decisions and tradeoffs. "How can you put a dollar figures on a life?" the critics ask.

And what about litigation? Although there are few air bag cases so far, one insider wonders what happens as air bags get older. How long are they guaranteed to work as designed? Five years? What happens if they fail to work or explode without warning?

A study by IIHS shows that only 5% of those surveyed remembered any problems when the air bag deployed. "Minor injuries from inflating bags aren't uppermost in the minds of those who've been in crashes," says IIHS Senior Vice President Allan F. Williams. "Despite minor problems, such as abrasions, drivers have a very favorable view."

One thing that everyone seems to agree on is that if more Americans wore seat belts, there would be far fewer deaths and injuries. In Europe, particularly Germany, almost all drivers wear seat belts. This allows small, lower-cost "face bags" to be used. Combined with seat belts, face bags provide the same protection as larger U.S. bags, which by design must protect unbelted occupants.

What many people don't know is that air bags can be dangerous for short people who sit too close to the steering wheel or for infants in rear-facing child seats strapped into the front passenger seat. Those who hit the air bag before full inflation can be injured. Babies in infant seats can be pushed face first into the passenger seat and suffer broken necks. The problem is, many drivers don't know about these potential problems.

Nor are many taught how to use ABS. "Driver education is critical," says Timothy D. Leuliette, president of ITT Automotive, a major ABS manufacturer. "We can't continuously make vehicles smarter for people without telling them how to drive them."

ABS requires some head- as well as footwork. "It's clear the manufacturers over-hyped ABS technology and that drivers don't understand how to use the brakes," maintains HLDI's Mr. Hazelbaker. "Studies have shown that when people are asked if they like their new ABS, they say they're great, but when questioned further -- asked what they think about the feedback when they're working -- it's clear people have never used them.

"They like ABS because it's a security blanket," he says. He suggests only those driving in ice and snow need ABS.

HLDI's research shows no real benefit to ABS. "They work on the test track but we believe we've found that the window in which they perform is fairly narrow." That's especially true considering the vast majority of accidents are low-speed fender benders where hard braking and steering around trouble doesn't happen, he says.

Although recent studies in Canada and Sweden reportedly show ABS does indeed reduce accidents, several studies done in the U.S. fail to show a statistical ABS advantage. In fact, a recent GM study shows vehicles with ABS are involved in rollover accidents 44% more than those without. But GM says the problem is the driver, not the brakes. That same study shows that total crashes were cut by 3% with ABS.

Mr. Leuliette says ITT research indicates that there are more rear-enders with ABS because cars with ABS stop straighter, raising havoc for vehicles behind lacking the control ABS provides. Even so, for the ABS-equipped car, that can be better than fishtailing and being T-boned.

About 95% of U.S. new cars and trucks will have ABS by 1998 or 1999. "This tells you there is a perceived safety value that it will help them even though it's not legislated," Eric Devore, chief engineer electrical & brake products in Robert Bosch Corp.'s Automotive Group.

"In the past seven years that cost has been halved and has the potential to be further reduced. And systems are better today than they were seven years ago," he says. Bosch says in 1978 ABS -- then available only in Europe -- cost about $2,000, or four times the current option-price posted for mainstream models.

The whole thing has insurance companies confused. Although some give a break to vehicles with ABS, even with the less flattering study results, they wonder why ABS prices are still fairly substantial in the overall scheme of things.

Some new safety-related features such as traction control don't significantly increase cost, says Mr. Devore. Others such as vehicle dynamics control (VDC) add more functionality than traction control because there are more sensors and more intelligence. The initial cost is high, he admits, because volume is low. Bosch's first VDC system sold in the U.S. will be on a '96 Mercedes to be introduced this November.

Safer seats could add even more cost. There's growing controversy over what role seats play to keep people safe. Should they remain upright in a crash? Should they absorb energy, and if so, how much? Should the seat yield in a rear-ender? "All of this requires a balancing act," says one engineer. It also means that seat suppliers can't over-engineer seats to make them safer. To do so could add cost that consumer just may not be willing to pay.

What's going to happen when all the whiz-bang technology becomes available? Some consumers already are nixing it. Chrysler, for example, asked buyers if they'd like a center high-mounted stop light that flashes rapidly in a panic stop. "No way," they said.

Other features are in the works, some that may catch on, others that won't. Just around the corner is a mirror with a turn-signal indicator that flashes an arrow so the driver in the next lane is acutely aware of your plan to move over. There are also proximity sensors that warn of vehicles in the next lane. They'll cost just under $ 100.

Intelligent cruise control would maintain the space between you and the car in front of you using radar or sonar technology. That could slow the number of rear-enders. "In 85% of rear-impact accidents the vehicle is already stopped. Any warning that could get drivers to react sooner could prevent or lessen the severity of accidents," says Ford's Mr. Henson. Trucks use it now, and the price is probably "about $200."

Further down the safety highway look for yaw sensors, intelligent cruise control or an all-weather imaging system that will show through fog or rain using cooperative radar-reflective paint.

Voice recognition for controls could also be big so that drivers won't have to take their eyes off the road to tune radio, or adjust other controls such as air conditioning and heat.

Might any of these Star Wars gizmos have prevented the accident between the Buick and the Tempo, or will they go too far at too high a price? That's what automotive marketers and buyers will have to decide.