I'm doing it wrong because I never negotiate. Either you want it or not.
I am doing it wrong because I never negotiate but I get what I want. The negotiation process is if you don't like the price then keep shopping till you do.
Most higher end markets find negotiation as an insult. When people buy exotic cars, negotiation is not even a thing you do, because you already made up your mind you want it. Then at that point the only communication to the seller is where you want it delivered.
I realize this isn't an exotic not expensive car but if he wants favor with the seller and expedite the delivery process, that's one way to do it