If you believe the bank didn't make a reasonable effort to obtain the best price, but simply "dumped" the vehicle, then you *may* be able to challenge the amount they are seeking, if they do come after you for the deficiency or unsatisfied balance. So, for example, a court could conclude that they should have gotten more for the car, and limit the bank to only seeking any remaining balance over that fair value. However, the mere fact that a car sold for less than fair market value does NOT, by itself, prove that the bank did anything wrong: such auctions almost always produce less than if the car had been sold oetherwise, such as by a dealer or through a private sale. Usually the bank will be upheld in whatever amount it did sell the vehicle for, and be allowed to seek any remaining balance from the debtor.