You would definately be better off trying to sell it to another enthusiast. Even then you're never going to get all your money out of it. When they look at the trade-in value, they just have a standard amount that they raise the value for things like "all terrain tires, alloy or custom wheels, premium stereo," etc. You can try to explain that you have $1,500 in your suspension and $2,000 worth of tires and wheels, but the dealer won't care. They'll just sell it to a used car lot at an auction. Then that used car lot will turn around and try to sell it for about four times what you traded it for.