I had an Audi 100. It had had a superb botch job after the middle silencer had rusted through and was replaced with a random length of exhaust. The plan was to scrap it at MOT time.
As the MOT became due a friend of a friend acquired a similar non-runner. After a bit of a chat I said he could have it when the MOT came up. FOC, I'd just need a lift home. His plan was to build a working car from the two.
The day came, and, despite my protestations, he gave me 8 cans of Kronenbourg as a thank you.
The next morning I woke having drunk 7 of 8 cans, realising that I had effectively swapped a car for a can of lager. Friend of friend woke to find the [my old] car had been stolen from his drive.
There are only losers in this story.