At the dealership
Urgency: "another buyer is looking at it"
Manufactured time pressure to short-circuit comparison and review.
What to say
“If it sells before I've had time to review the numbers, then it wasn't my car. I'll take the night.”
What it is
Claims that another buyer is about to take the car, or that a price is only good today, are designed to prevent shopping the deal or reading the paperwork. A fair deal survives a night's sleep and a second quote; walking away almost never costs the actual car, and if it does, another equivalent one exists.