In reply to:

You could also do "If the empeg powers up without me expecting it" (e.g., the criminals started the car) so you can get a head start catching them before they're "out of range".

That, and with some of the other computer control related projects, you can implement a device to allow you to shut off your car from your computer (assuming you are still in range)... or have some other form of override :)

Driver ejection seat?

Kureg