@Ragman,
Sorry but a car owner is not responsible for laws being broken unless there is proof that he was also the driver.
Nor is he under any legal obligation to talk to the police.
Keeping his mouth shut and refusing to talk to the cops if they would call on him and he is petty must bullet proof.
Say these magic words I will talk to my lawyer and see if he will suggest that I talk to you over this matter in the meantime I am not going to talk to you so please have a nice day.