You seem to be asking about the passive (or “smart”) systems that automatically transmit a signal when the driver gets close to the vehicle to unlock the doors and disable the theft-deterrent systems. All major manufacturers now offer them. Some require touching a door handle to unlock doors; most allow the driver to start the engine by pushing a dashboard button or turning the ignition switch without using a key, and some allow remote starting.
Some view the system as another sign of the apocalypse because it makes us more dependent on electronics and adds complexity to cars, but it allows drivers to keep their high-tech “key” in a pocket or purse, reducing the chances of losing it. If you’ve ever had to fumble for a key during a downpour or while holding an armload of groceries or a squirming child, you’ll probably appreciate the convenience.
But if you have to replace one, plan on spending at least $200, probably more, and you could pay steep additional charges for programming the car’s computers to recognize the new smart key. And before you walk away from your vehicle, you have to remember to turn the engine off with the dashboard button or keyless ignition switch.
Conventional remote control functions for cars such as unlocking the trunk lid separately from the car doors, centralised door locking, and opening the side windows from afar are widely spread today increasing user convenience.
RFID-based remote control functions combine conventional remote control functions with enhanced security features. One example for a smart remote control function is automatic opening and locking of car doors when the RFID transponder resides in the range of the car enabling keyless entry. Equipped with advanced encryption standards, the transponders reliably prevent interception and spoofing of the transmitted signal.
Further functions that can be tied to the presence of an RFID transponder in the range of the car are security features such as activation of the alarm or anti-car-hijacking features.