* "Don't tell 'em you have a trade-in until you have agreed on a price for the one you are buying".

Um...NO. Why would you do that? Besides the fact that lying or misdirecting is an unnatural and uncomfortable process for most people, besides all the time it will cost you--HOURS--as they now have to appraise your trade and put an accurate value on it (while fantasizing about stabbing you in the chest), it has skewed your financing deal because your interest rate quote was based on a certain LTV(loan to value) that has now changed. If you did not work a financing deal, and decided only on a purchase price, you have locked that price in and left only one more negotiable item.

Working both sides against the middle will give you more

room to work. Your trade-in will not suddenly gain (or lose) value. EVER. It is worth what it can be sold for at that moment, never more. Depending on several subtle factors, or the skill(or lack thereof) of the appraiser, one can gain a small monetary advantage or concession on occasion.

When dealers move money from one car to the other, it is because that is what you are telling them you want to see. "Give me more for my trade!" Okay, here you go. " Now, what's the deal with the other price?"?" If you know where the numbers should fall on both vehicles, you will at least be able to squeeze from both sides. Just like they will be doing!

* "Don't talk about monthly payment"

Okay, but isn't that how you work out your own budget? By the month? So, if your main deciding factor is the monthly payment, then perhaps you should mention that. Now, you DID work out your likely interest rate and loan term, right? No? We should probably slow things down a bit, then.

Incidentally, you can eliminate this issue by getting your own financing. Why not do that right now?

* "Beat the dealer"

Huh? How will you beat the dealer? If they sell you a car, they have been successful. That is what they do. If the deal is not advantageous to them, they will not sell you a car.

When you enter into any event in your life with the idea that someone else has to lose in order for you to be successful, that event is taking too much from your life-force and should be put on hold.

If you are happy with your deal, if you have the car you want and are paying the amount you determined you could comfortably pay, then you have been successful. Be happy! That is the very definition of winning a car deal, and if you need more evidence that you won, take a victory lap around your neighborhood, around your part of the world. See the sun, the sand, the mountains, the ocean ? Yep, you won.

Oh, yeah..."Bigfoot"? Just a giant prehistoric ape-like creature that lives in the Pacific Northwest. Nothing more.