the car is legally the person that owns the rights to it i.e. the person that holds the registration document. the person that has taken finance against the car is the debtor therefore they need to pay the finance company irrespective of whether they are in possesion of the car or not. You could advise your friend to issue a Small Claims summons against the owner of the car but unless there was some contract between them in the first place in that the owner agreed to payback the person that took the finance, I doubt that it would be upheld.