never load your parts on to anybodies trailer/truck or let it leave the location it is sitting until there are the bills in your hand. They are your parts till cash is exchanged
I have pissed a few people off by this tactic, but i know that i will not be out anything and i know if he/she really wanted it that badly he would have the cash in hand.
I even deal with family this way because i have too many dutch relatives, but i am not dutch. My mother is :-#