The ultimate bet in terms of personal confidence in an illegal Street race or the like. Two racers put their cars on the line by offering their registration slips as winnings. The winner of the resulting race wins the opponents car for good. This is exhibited in some of the Fast and Furious movies.
Friend 1 "hey man what's up?"
Friend 2 "I just won me a new car last night, racing for pink slips."
Friend 1 "Wow, you're brave, putting your car up like that.
Friend 1" well I wanted that car man.