I have read to go in, find a car you would take for the right price, but don't want. Low ball an offer, work with them for a few hours, when they won't take your lowball, walk out.
Come back a cpl days later for the car you want.
Start working it, keep them on it for hours. Come in a little later in the evening, about an hour before close. Keep them past close.
For me, the last 2 cars I bought. Each took about 10 minutes. My BMW, I knew what I would pay for it. I told the sales guy. He said, my manager will say no. I said go ask him. He wouldn't. I told him there was now way I was paying what they were asking and to tell the manager my offer. AFter about 6 times of telling him, he went and got the manager. We got done in 3 minutes.
When I bought my wifes ford explorer, I had access to the dallas auction info. Went to the dealership, looked at a gold one. Nice, but a little more miles than I wanted for the price. Went backa month later, car was still there. Drove it again, just as a test vehicle. Before I left, the manager came up to me and told me he had the car for 45 days, and it was going to auction. He said I could have it for what he would sell it to his sales guy, $550 over what he paid. He pulled out his invoice from auction. It was the same price I knew he paid from seeing that car on the auction wire. He sold it to me as a certified vehicle. We got done in about 10 minutes.
TXL