Well well well,
get a loan from the bank first, that takes the payment thing out of the picture.
when a salesman brings you the 4 square (it's the paper that has the price in the top R corner what they are taking your trade for in the left and the down in the left bottom and payemtn in the bottom R) they try to keep you off the price of the car by changing payments (extending a loan to make the payments lower.
Tricks, if your smart youi not buying a new car, when you look for a used car look for the cars on the lot with like a little smiley face sticker or star on them (only a few casr will have them) this tends to mean that the car has been on the lot for a while and the used car manager want to gone, tose cars can be had for a good price.
Secondly DONT BE A D1CK, it wont get anything done, theve seen it before (also the guys that come in like rambo tend to be the ones that get raped on the 4 square).
Now what you want to do is bring a woman with you (like a girlfriend or wife) this way you can be into the car and they can b1tch about the price "well we really cant afford that, we wanted to pay xxx OTD (out the door). THIS works well.
BE nice but stick to your guns.
finally when they ask you to sign the 4 square, likke they say "sign here saying that if I can do this then you will sign and drive the car away" sign it; that piece of paper mean jack chit, but unless you sign the desk guy (the sales dudes boss) wont negotiate because it looks like you are not willing to play ball/ or are a jack.
If you are buying a new car buy it from the "fleet" department, these guys only get paid more for volume (sometimes they make a flat rate per car sold, hence the reason they may have to sell 25 cars to have a good month where as the normal sales guy will sell 9), you can bounce numbers with the fleet guy (or if they have a internet dept. use that) from lot to lot, usualy these fleet/internet guys will drop there pants as they are all about volume). Also saying you are a cosco member sometimes makes them sell you the car for like 250ish over cost (new cars only) and yes they will ask to see the cosco card.
Buy the car at the end of the month, as they have sales competitions which go off cars sold.
uhhhh.. cant think of anything else right now, oh yea, if your really smart you will take the check the bank gives you, get a auto trader and try to get a car that way, those tend to be the best deals, sometimes you can find someone that is still ows money on the car, and you can pick it up CHEAP, best trick is to get a older autotrader (like 3 or 4 weeks old) fin the a little steeply priced cars, and call them as those people tend to wake up when the bill comes in the mail for the next payment yet the phone isnt ringing w/ buyers!...that or make a friend and go to the auction (no this is NOT the public auction)
also the I'll give you 200 bucks under the table thing wont work, the guy at the desk needs to make money too, and the salesman isnt even CLOSE to the finaly word. also dont buy any of that crap in the F&I office, except GAP insurance (if you insurance provider doesnt have it) that stuff is also price negotiable.