A hot potato: Keyless car theft has become a growing issue recently, as carjackers have learned how to hack wireless key fobs. Safety measures to fight these new techniques exist, but recent comments from a British car association president bring them into question.

Since the rise of fobs that automatically unlock and start cars, car thieves have developed ways to circumvent their digital locks, and security measures have evolved in response. The situation resembles the cat-and-mouse game between hackers and security throughout the IT world.

Recently, cheap electronic devices have emerged that let thieves duplicate a fob's proximity sensor signal from within a few meters. They can then boost that signal to an accomplice standing next to the car, allowing them to open and start it. Expensive luxury cars --- more likely to use proximity sensors --- are obvious targets.

Police and manufacturers suggest car owners keep their fobs far away from their vehicles and away from doors and windows when not using them, ideally in a metal or aluminum container to block the signal. Sellers also offer pouches lined with metal or wire mesh which block signals when storing fobs.

However, current measures are not enough for the president of Britain's Automobile Association (AA), Edmund King. This week, King told The Telegraph that thieves stole his wife's 50,000 GBP Lexus despite her fob being in a bag in a metal box in the part of their house farthest from the car.

In response, King has begun storing the fob, bag, and box in his microwave oven. Even if this solution works, it is certainly impractical. A more robust shielding material for containers is a logical step, although that may be more expensive.

King has also resorted to an older car security measure that was quite popular in the 1990s --- a steering wheel lock. He's considering installing a security post and a gate at the entrance to his driveway, which for most is prohibitively expensive.

The core of the problem is the driver's need to expose the fob when entering or exiting the vehicle. King suspects someone caught the signal from his wife's fob as she parked the car after observing their daily routine.

The ultimate solution may be to disable the proximity sensor, which many fobs allow. King thinks car manufacturers should always inform customers of this option.