Try selling you car on ebay. Now remember, often times ebay is considered a hotbed of "good deals" so you may not get exactly what you owe on your car, but you will probably get better than $8,500.

To purchase my new Xterra I had some cash but also wanted to trade in my '92 Mitsubishi 3000GT. This particular model is worth about 5K in mint condition, which mine was not. Mine had 169,000 miles, a major electrical problem that interfered with shifting (automatic transmission), and a torn leather seat. The dealership offered $500 for the trade!!! I put my car on ebay, mostly for kicks, and it sold for $1875 to an out of state buyer who was looking for a car to fix up!

Good Luck.