There are many different types of buyers that come into car dealerships and they are classified into certain categories and the negotiation process is governed by the type of buyer they are. You want to avoid being classed like this because the less you let them know the better it will be for you. You want to know all aspects of the transaction from the purchase price, to the trade difference, to the payments. Let me show you these different classifications.

The first type of buyer is the difference buyer who is mostly concerned with how much the difference will be between their trade and the new vehicle. They may say something like this, ?Your car sells for $20,000 so I will give you my car and $10,000 for it?. In many cases they are way off the mark, but this is how it starts. The salesperson will take the person's arguments for why he thinks the trade should be done for these figures and use them against him.

The next buyer is the allowance buyer. This type of buyer isn't really concerned with the true worth of his vehicle, but with how much he will be allowed. The danger of going into a dealership as this type of a buyer is that you are just leaving yourself wide open. For instance you come in and say, ?If you will give me $6,000 for my car we have a deal!? The salesperson will say well, I can't allow you that much on this car, but on the one over here I can. Now they will move you to a vehicle that has more mark up and probably dealer incentives and rebates too that you will never know about.

The payment buyer is the next type of buyer seen at the local car dealership. These types of buyers really don't care about the price, the trade difference, or the trade allowance. All they care about is the payments. These are the buyers that car salesmen pray for because they are the easiest to make money on. They will come in and say, ?All I care about is the payments, if you can get my payments to $250 a month we have a deal.?
If the person doesn't give a payment the salesperson will pull a huge figure out of the air and shoot it at them just to get their attention. Now once you bounce back from the ceiling they will keep coming down until you agree on a figure. Now they will put you on a car that they can finance for way less than your figure and they pocket the difference.

Now do you understand why you don't want them to know? Keep it to yourself and be concerned about all of it.