Ditto here. Once I took emotion out of it and decided I was willing to pay X when I went in. If I am trading, I look for one number, the Out The Door price. I set my target for the out the door number and if they meet or beat it, I write the check.
If it takes more than about 20 minutes to come to a price, then I leave.
When I bought the Vibe, I drove it, mentioned what appeared to be a tire balance issue, negotiated a price contingent on the issue being resolved to my satisfaction. I said I'd be back with my wife as we were going to title it jointly and I refused the offer to take the 254K mile, '94 Geo Prizm on trade for $300.
We came back, I asked them to do the paperwork while we drove it, it was good. oilBabe and I signed the paperwork, and drove away in about 30 minutes. The longest wait was for the salesman to take it down the street to fill it up
I knew what I wanted to pay, and thought I got a good deal, so we wrote the check. No nonsense.
They even honored my request about the license plate frame. I said you can put one on the front, but any on the back will be replaced by my university frame off the Geo.
I sold the Geo for $1200, so that was a win as well! No drama, probably took an hour all told to buy the car.