[nova]

First thing he needs to do is get out of the realm of "I think" and get into the realm of "I know."

Go up to or call the CU and just ask them. "I'm having financial trouble, what would happen if I turn in the vehicle to you and the auction doesn't cover the loan balance." Sometimes that outcome can be negotiated if you turn it in because then they don't have to pay for repo.

Once he knows what will happen, then he can start deciding what the best course of action is.