I have a 94 mustang for trade in return for a 1996 dodge 2500, which is my brother in laws vehicle. I'd like to take the $6500 he wants for it, and use that as a tax write off for the business. But, if I trade, can I still write that off? Should I create a bill of sale, even though no money will change hands? Is it ligit or not? Any suggestions how I can obtain the write off?