Originally Posted by grandpapa
You sell your car for $12000. You still have to pay the bank $15000. So $3000 different. Now let say your new car is $40000, I don't think you can ask them to add that $3000 into the loan since it is not related.
It was just an idea I threw out there. It would only work if the financing for both vehicles was through the same finance company. It would be worth bringing up with the dealer; the worst they could do is say no, which is the answer I'd expect.
Oh, and it would be $9000 rolled into the car loan, since the dealership was only offering $6000 in trade. $9000 in unsecured credit would not be cheap.
Your best bet is selling it, even if you have to temporarily reduce your life savings by an extra $12000 between the time you pay off the loan and sell the vehicle.