Originally Posted by KERMIT

You should understand what you are buying, however knowing every detail won't do you any good. In fact, if you prove that you know everything about the car then you have given up a powerful negotiation tactic. They know that if you entertain negotiation that you "want this car!".

In fact, I recommend you know what you are buying. Just don't flaunt that fact.

Like I said, you will get further knowing how to negotiate than learning more detail about the car.