I just always put a few sentences in the desciption/details such as :
I have sent $xxxxxxx + 3% for fees. This money is for the purchase of E90 M3 Muffler Delete Pipes shipped to my door. The pipes are used but in excellent condition with zero fitment issues on a stock E90 M3. No rust or cracks. If any of these conditions are not valid, return of this payment is required.