Surely there is an easier way? dont most modern cars have a Bluetooth connection? Why cant the police just log into the car via Blue Tooth and switch something off, then it wouldn't restart until it had been to a garage. I dont know much about cars but i have seen that garage documentary on TV where they use Blue tooth to talk to the main electronics hub, on there the guy was doing something and commentator warned if he got it wrong it would disable the car.