You would be better off, and probably get a better deal and price just selling the car and/or trailer and then having CASH to purchase the airplane that fits your needs rather than an airplane someone is willing to trade with as the criteria for purchasing it.
I don't take trades. I figure that if the other party can't sell his item, then I wouldn't be able to either. Besides, it almost always seems that they think their item is made out of gold and mine is near worthless.
Serious buyers bring cash. Cash gets the best deals.