Why the friend's bankruptcy is a problem is that he CAN NOT be making any payments on the car. It is ILLEGAL for him to pay one creditor preferentially during a bankruptcy. The trustee decides who gets paid and when.

Unless the person is in a place to reaffirm the loan after the discharge, the borrower is going to be discharged from the obligation. The car can be repo'd and is almost certainly upside down and they will come after the poster here for the deficiency.

Since he only agreed to pay the loan and is not an owner, he can't take possession of the car himself.