"Lizard" - the guy that sneaks up on the lot weekly that never buys but lurks.
A "dagot" - - this was used on me my 2nd Sat out of college selling cars. I went out to wait on a couple at 10mins to close, 30 mins later I came back inside and my boss was waiting at the door, I was pumped, had his name, phone, address, and was to call him Monday to show him a new Sierra. My boss said "That's f-ing great, that DAGOT was here 3 weeks ago and before that 2 weeks ago and kept me late, so dont go out there anymore when he pulls up at closing" - I asked what is a DAGOT; he said "Don't Anyone Go Out There, and when you here it lock the door and get away from the showroom so he doesn't see you" As we left he asked if I wanted to go get a beer with him of all things, no - I wanted to sell a truck. 2 weeks later I sold the guy a Sierra. And later that week when we were all at the bar, the GM had us all leave the bar with the bill on the table when the desk manager went to the bathroom. Story was he later told him to never walk out on the dealerships customers at 5 mins to close.