Before you head for the dealership you will already have done your homework, so you will know the dealer's invoice price, whether rebates or dealer incentives are available, and your target price, as well as where you plan to start bidding. You want to start the bidding as low as you reasonably can, but not so low that you will seem like an uninformed buyer just making a low-ball offer.

Pull together a folder showing your data and sources on these details where you can readily refer to them yourself or show them to the salesman.

At the showroom. Establish quickly that you are a serious buyer, not a browser. If you come across as just shopping, the salesperson will be eager to move on to a likelier sale. Don't say: "I'm looking at the Ford Taurus." Say instead: "I plan to buy a Ford Taurus LX within the next two weeks and I know pretty much how I want it equipped. I will buy where I get the best price. Let's talk about it."

That keeps you in control. The salesman wants to know as much about you as possible to start spotting potential profit points. Stay pleasant, but just turn away questions and say: "We can talk about me later. Let's talk about price."

Focus on the invoice price. As soon as you can, try to switch the discussion away from the MSRP or list price to how much you intend to bid over the dealer's invoice cost. Bring out your Internet printout to show you have done your research on this. The salesman may well say: "That is not the right invoice price for the car." He or she may in fact know less than you do, since traditional dealer training focuses on the MSRP, and many dealers do not give salesmen the invoice prices. Say: "This is the invoice price for the car I want with the equipment I want." Show him your printout.

Start low. Though your target is $200 above invoice, you need to leave room for the dealership to budge you a little. So start out bidding at the invoice price on a car like the Taurus, where a rebate signals you to negotiate hard. You know you are entitled to the $500 consumer rebate that was offered recently, but don't bring that up yet. If that $500 had been a dealer instead of a consumer sales incentive payment, you would start out bidding to try to capture at least half that money. In that case, you would bid $300 below invoice and make it clear how you got that figure. "Since the dealership stands to get a $500 payment from Ford as a sales incentive, $300 below invoice seems fair."

He who hesitates loses. At this point, the salesman is likely to say something like: "I think this is way too low, but I will take your offer to my sales manager and see what I can do for you." He or she may not even intend to talk to the sales manager, but plans to keep you waiting in the glassed-in office to pressure you into a higher offer before even seeking approval. Tell him or her you do not intend to wait long. Then don't just sit there. Wander around the showroom or go outside to look at other cars. That usually brings the salesman back quickly. It's likely that he will bring the news that your initial offer was not good enough. At this point, if you started the bidding at the invoice price, agree to $100 over invoice.

If you get it, take it. If the dealership has a car in the color and equipment you want, and the salesman offers $200 over invoice, accept the offer. If not, get the best offer and take it to another dealer. If the second dealer beats the original offer, keep the competition going -- play it back to the first dealer. When you hit your target or come as close as you think you can, agree on the price. Now, and not before, is the time to talk about a trade-in. You already will know what your car is worth from checking local ads and looking up your model on Websites such as Edmunds.com and the Kelley Blue Book. If your car is a popular model in good condition and you are sticking with the same brand, you might match or slightly beat that price with your new-car dealer who sees potential profit in selling your used car. If the trade-in offer is a good one, say yes. If not, plan to sell it yourself or take it to the used-car lot of other dealers for a price quote.

Once your price and trade-in are set, you still have to finalize the deal. In our next section, we tell you how to close.