Thieves in the UK won't get far stealing a car outfitted with this tech. It uses the car owner's keys and cellphone as an identification method. Try to start the car without the cellphone and it gets marked as stolen. Police can then track the car and prevent it from restarting once it's been turned off and the car is stationary.
This could be real hassle—not for the thieves but for the car's owner. Lose your cellphone at the mall and the cops follow you home? What happens when you get carjacked and the phone is being charged in the lighter socket? For a parked car, this might make perfect sense—if it didn't cost $607.
Cell phones: Your other car key [Foursprung]