How long ago did he buy the car (you said buy, I’m assuming that’s what you meant, not lease)? If it was more than, say, a year ago the first option I’d explore is getting a refi on the loan. Go to some banks and see if he can get a better deal with either a lower interest rate or a longer term. Adding on another year may help out.
Another option is to figure out how far upside down he is and see if he can sell it back to a/the dealer.
Yet another option, and I don’t like this one, is to refi his house (if he has one) and roll it into that one by taking some cash out. The reason I don’t like that is because right now if he defaults on the car loan, they’ll take his car, if he secures the car to his house and makes his house payments higher and ends up defaulting on that, he could lose his house. That’s the same reason I always advise people to never, ever, ever roll their credit card debt into their house when their doing a refi and the lender says “I see you owe such and such credit card $3000, do you want me to take $3000 out when we do this and you can pay them off”? Now you’re paying that debt off over 30 years and securing it to your house.
But we need more details. Do you know when he got the car, what he owes on it, what the buy out is, what the KBB value is, what his payments are, how much longer he has on it? Any of these things will be helpful, even necessary in coming up with ideas that are anything other than just speculation.
As others said you can’t just ‘turn the car in’ (in most cases). It doesn’t belong to the dealer, it belongs to the lein holder. At worst it’ll end up getting ticketed and towed off their lot and sitting in an impound lot, at best, very best, they’ll help out. But what would probably happen is that the loan is through the dealer/manf. and the dealer would let them know and they’d repo it sooner rather than later.
Barring more details, I’d start by seeing if I could renegotiate the loan. Even calling the current bank and seeing if I could add another year to the payments. That might be enough to knock $50 a month off.
But, like I said, if you can get more details, it would be really helpful.
ETA, he should check the website where the payments are made, I’ll bet there’s a link or a line that says “Need help making your payments, call us at…”. Maybe start there.