Key fob theft warning is just an urban legend

Dear Tom and Ray:

I got an e-mail this morning from our company's internal security department about locking your car with the remote key fob. The memo cites the story of a woman in a shopping center who noticed two guys in a car watching her, and then, after she locked her car and walked away, she heard her car unlock. It says that car thieves have a device that can capture the frequency of your key fob, and then use it to unlock your car while you're in a store. The woman claims that this was explained to her by the police. Is this true or an urban legend? Thanks.
-- Mike

Ray: It's an urban legend, Mike. When locking key fobs were new, back in the 1980s, they would be set to a single, permanent frequency. And I suppose, in those days, if a thief had the right equipment, he potentially could capture the frequency and gain access to the car.

Tom: But there are two reasons why that's extremely unlikely today. First, key fobs now jumble their codes. So each time you use the fob to lock your door, it generates a unique code that it uses only that one time. While there might be equipment capable of breaking through that system, it's more likely to be owned by the "Ocean's Eleven" crew than by a common burglar.

Ray: That's the second reason why this story is unlikely to be true: Most people who break into your car to steal something off the seat are opportunists, not master planners. These guys go looking for a car that's been left open, or they'll see a computer on a seat and break a window to grab it.

Tom: Keep in mind, also, that they can't steal your car with the key fob frequency, even if they could obtain it, since the ignition system has its own immobilizer.

Ray: So rather than worry about this sort of high-tech operation, you'd be better off following the more basic rules to avoid car break-ins: Don't leave valuables in plain sight. Remember to lock your car. Park in well-lit, populated areas. And don't ever leave your car in my brother's neighborhood.

(Car Talk is a nationally syndicated column by automotive experts (and brothers) Tom and Ray Magliozzi. Write to them at the Car Talk Web site.)