First post of a long-time reddit reader. Apologies for any mistakes.

I recently sold my car (Hyundai Santa Fe, 2013) to an acquaintance. I originally planned to sell it to a dealership, but a friend of a friend mentioned that he was in the market for a 2nd hand car and was interested. I offered the car to him for basically the same price that the dealership offered to me, which in the current environment, I thought it was a good deal for him. The car was well taken care of. He took it to his mechanic for an assessment. A couple of minor issues came up from that, we split the cost to fix them and closed the deal.

A couple of months after the sale, the engine died. Fixing it would cost almost as much as the car itself. The guy is now going after me. Even though he acknowledges that I am not legally obliged to return the money, he thinks it would be the right thing to do, because "I sold a defective car" to him.

I regret not having sold it to a dealership instead and put this guy in such a position, but at the same time, I don't feel responsible, especially after he had the car inspected and nothing major came up.

Anyways, I thought I'd ask: what would be the right thing to do?

Thanks for the advise!