It's been decades since it…
It's been decades since it happened to me, but I traded in a GMC Jimmy that the dealer was supposed to pay the loan off. Imagine my surprise when a GMAC rep showed up at my door to repossess the truck I no longer owned. I let the rep know that I traded the truck in and pointed them to the dealership... fortunately, it worked out in the end and I never heard more about it.