In the UK a few years ago there were reports of people's license plate numbers being duplicated and stuck onto vehicles that matched the genuine vehicle's description and then used for various crimes, like filling up with petrol and driving off without paying.

This tech would be susceptible in a similar manner - stolen vehicle goes out and drives badly etc. etc. The only identifier would be the licence plate. How about using their phone account as the identifier rather than the vehicle?

Anyway sounds like an idea ripe for misuse and "feature creep".