If a stolen vehicle hits your car is the owner's insurance company liable?

Answer 1

The thief of the car is responsible, not the owner of the car. How can the owner control his car being stolen? However, if the owner or person in charge of the vehicle left the keys in the ignition, liabilty may attach in some jurisdictions.

Answer 2

No, of course not. The vehicle owner is not liable for the actions of a criminal who stole a vehicle. To hold the victim liable would be a second victimization of that person.

The liable party is the thief who stole the car and did the damage, not the already victimized owner.