4. Don’t drool over the car.
Never say aloud you want the car. “You don’t have to be a Vulcan,” Steven says, “But don’t swoon. You don’t need a poker face, but don’t make it obvious, either. If you tell the seller ‘I’m considering this’, you show interest without showing overt pavlovian interest.”
Ultimately, negotiations will come down to the seller’s ability to read you as much as it will their actual monetary limit.