It is coupled with RFID chips in your key. I actually find it very convenient on my Hyundai. I can walk up to the car door and open it, it unlocks automatically because the RFID key is in my pocket. I can sit down and start the car and take off without ever removing my keys from my pocket.

It's also very convenient for opening the trunk without a key as well. It has proximity sensors by the driver and passenger doors, as well as the trunk.

> Wouldn't shifting to neutral make the engine rev up really high? Does the computer limit the RPMs to prevent damage?

Yes, the computers do.

However, if you're going to have an accident, engine damage is pretty low on the list of concerns, even if you ignore the fact that accidents cause engine damage.