AskMeCha: Fair "rent" for borrowing a wreck?→[More:]
We sold a tenant our old 1997 Chrysler Concorde when a ball joint failed and it needed more body work than it was worth (besides, it was a lemon from the day we bought it used around 2001). The guy paid us $350 for the car and did the work himself. Fair enough.

Then we needed a car when our van went wonky, and he and his mom lent the car back to us for 12 days. Now, I would like to pay him a fair price for this. But this would come in the form of a credit against back rent. In effect it almost doesn't matter, since it isn't cash, so I can be generous, and I'd like to create an incentive that the money owed to us can be whittled down, but what would be appropriate?