It's interesting that the approach to in-vehicle navigation has come from an eclectic batch of companies with varied expertise. Bosch made its name in braking and steering components. Siemens

began as a telegraph company in 1847, Alpine came from the car audio side of the dashboard and Denso first earned its reputation in engine components.

Now they're battling it out in a big part of what the GPS Industry Council estimates will be a $3 billion U.S. market next year. Estimates by Allied Business Intelligence peg the total at $7 billion - $14 billion worldwide - by 2005. In-vehicle navigation will account for one-third of those dollars, or about $4.7 billion, says ABI.

The Global Positioning System (GPS) satellites have been triangulating positions from on high for nearly a quarter of a century. As the technology spread from the military to commercial navigation, then pleasure boaters and over-the-road truckers, it was bound to work its way eventually into the family car. And competitive forces virtually require that luxury carmakers all offer some sort of navigation system today - an interim spot on the trail that began with car phones and that will progress to in-vehicle computers that will soon offer such things as e-mail and personal address books.

How well do these navigators-in-a-box work?

WAW corralled five cars with systems from four of the main players in the vehicle navigation game: Germany's Robert Bosch GmbH and

Siemens AG and Japan's Denso Corp. and Alpine Electronics.

The cars included a Jaguar S-Type and Lexus LS 400 with systems from Denso, a Porsche Boxster courtesy of Siemens, Acura RL with Alpine system and Mercedes S500 fitted by Bosch.

Most automakers were reluctant to pin a price on the option, but those that did offered pricetags of around $2,000 to $2,500. Most nav systems are bundled in with a horde of other "standard" upscale features or feature packages that include leather seats, stability control and premium sound systems.

Five editors took a night in each car and tried to find their way to Aunt Gert's, the movies or to and from work.

We wanted to know how easy these systems were to operate. Can you read the screen? Are the map zoom-scale increments adequate? Are the point-of-interest listings for banks, restaurants and gas stations useful? Can you change settings while zooming down the freeway, or do you have to pull to a dead stop to enter your destination?

>From those questions and others, we crafted a semi-objective survey with a >possible 110 points.

Sitting at the top of the points list in nearly a dead heat were systems by Lexus/Denso and Acura/Alpine. But the Alpine system edged into first place largely because it was the only system with a very user-friendly touch-screen data input. One editor waxed profusely: "An outstanding system in almost every way. One of the few I'd pay extra for. Glorious detail in the maps and dead-on accuracy at all times."

Aesthetically the Lexus/Denso system also won fond spots in our hearts. Nav controls on the Lexus are placed around the outer edges of the LCD display screen. Buttons are large and easy to operate, and the cursor moves quickly through the alphabet when typing in a destination.

A knock on the system was its singlemindedness. It locked in too literally on a route prefrence of "freeway" or "shortest route" and was slow in recalculating a route if one strayed from the originally assigned path.

The Boxster/Siemens system also got high marks for the extensive trip data available and for ease - relatively speaking - of data entry. Scrolling through the alphabet for street address and city data input came via a knob that turned.

Says one editor: "Near perfection of the 'clinical' approach to navigation. I like the ability to split the display between nav and audio/phone functions. Disappointed in the accuracy, though. Sometimes it was hundreds of feet off the mark."

Appeal of the graphics on the Porsche/Siemens nav system brought mixed results. Some editors liked the high-contrast, almost electric look of the screen, while others found it difficult to read. One editor complains that the spinning-knob selector worked in the opposite direction than she expected.

The Mercedes/Bosch and Jaguar/Denso systems received the heaviest knocks.

Says one of our raters, "The Mercedes system is the most counter-intuitive among the candidates. Negotiating the input data is awful." To explain: Mercedes uses a complicated set of "cursor" buttons mounted around what is ostensibly the radio volume control knob. In the radio mode, controls to the right and left of the knob serve as station "seek" up and down buttons. In nav mode the "volume" control knob is a push button selector (providing the equivalent of a mouse click) and the "seek" controls serve as cursor controls. Confused? So were most of our editors.

The Bosch system also provided the least map detail, eschewing the labeling of most side streets even in the tightest zoom-in mode.

One editor asked for the shortest route to work, which would have required at least a 12-mile jaunt on a freeway. "It never got me anywhere near the freeway, and at a T-junction it couldn't tell me which way to go."

Sums up another rater: "Given the option, I would not choose to have this system in my car."

To be fair, every in-vehicle navigation system in North America that offers turn-by-turn route guidance uses NavTech's map database. Yet how that data interfaces with the hardware can offer slightly different results.

A couple of editors complained of confusing directions offered by the Acura/Alpine, Lexus/Denso and Porsche/Siemens systems, too.

The Jaguar S-Type/Denso system produced the most carping. The screen was too dim and was not placed well in the driver's sight line; the cursor control was too jerky; the map database was the most spartan and didn't list cities that were part of a pull-down list on the other systems. Good points were given for the friendly voice that offered the "turn right in 600 ft.," "exit ahead," or "if possible, make a U-turn."

Overall, our preferences were decidedly for touch screen controls that were not locked out when the car was moving. We know it can be dangerous, but a careful driver sitting at a stop light should be able to program his or her nav system without putting the car in park. Lacking that, a passenger should be able to enter data while the car is moving.

One editor also took a brief look at a decidedly down-scale alternative: a Delorme PC-based GPS. You installed the software, dropped the map database into the CD drive on your laptop, plugged the GPS receiver into a serial port and punched in your destination.

Advantages included the larger laptop screen and a price of only $200 for the hardware and software (exluding the $2,000 laptop). It also was the only package that mapped local streets for a small rural village 75 miles north of Detroit (where that editor lives).

Disadvantages: The laptop slid around on the seat. The GPS receiver slid around on the dash during hard cornering. It took quite a long time for the system to lock onto the vehicle location. And the laptop battery died (running that CD drive really eats up the juice) about two-thirds of the way through an hour-long trek.