My car has an alarm that I know works to immobilize the engine as it happened the first day I owned it.... The car was towed to the dealer who had the alarm guy come out to fix it.
Smart keys / keyless entry are now easily defeated by thieves who have a box they carry that somehow unlocks the car.
I think they're using the HackRF One or something similar. Its a software defined radio that can be used to capture signals and then you can send them back out.