It becomes my personal ID card, and I'm not sure I want that

As with any new technology, the trend toward passive entry is prompting engineers and designers to re-think some long-held assumptions about security systems and the way people interact with their vehicles.

That leads to other questions: If the standard ignition lock and key arrangement goes away, do we revert to 1950s-style push buttons? Or, in this wired world of satellite communication, why not let OnStar unlock our cars and start them, too?

And if latches can be electronically actuated, do cars of the future need door handles?

“I'm never buying a car without door handles,” says Douglas Patton, a senior vice president of engineering at Denso International America. “Maybe that's fine in southern California. But can you imagine waking up on an icy morning and having to pry your door open somehow?”

Even though auto makers love to create concept cars without door handles, most designers say that, for the sake of practicality, they probably won't disappear.

“It looks great, but it's not a very practical consideration,” says Ford Motor Co. design chief J Mays.

When it comes to radical technology such as passive entry, Patton says Denso takes a conservative stance. He notes that the technology can backfire and pose serious threats to individual security.

For instance, the so-called “smart card” employs radio-frequency technology, which allows it to link up with a host of personal security devices.

“OK, my garage door works on the same technology. Now my light switches come on in the house before I walk in,” he says. “You can have cameras look around the house to make sure it's safe. It becomes my personal ID card, and I'm not sure I want that.”

If a traditional key should fall into the wrong hands, it's like giving a blank check to a potential thief. If a smart card should fall into the wrong hands, it's like handing over the entire checkbook — and a pen to fill it out.

“And if you just want to loan your car to someone,” Patton asks, “do you really want to give them your personal ID card?”