I live in Washington state and I recently purchased a car from a dealership and also traded mine in at the same time. I estimated to them that I owed $7900 on my trade in, give or take a couple hundred. They wrote up the purchase order using the $7900 number, I took it to the bank, the loan was approved and everything was signed between all parties. I've had the car for a week now and the dealership just called saying that when they called to find out the pay off amount on my trade in, that it was actually $8100 and that I owe them the $200 difference. My personal stance is that I would have thought they'd have done their due diligence and called to find this out before drawing up the papers and having everything signed. My question here is do I owe them that $200 or is the deal done? Thanks in advance.