The first thing you need to realize when going to a dealership to buy a car is this. The salesman's agenda is to make the best commission possible.
Your agenda is to get the best deal possible. You must understand this mindset. Most people are too naive to realize what is happening when they are being sold a car.
They are not thinking like the salesman, who has been there every single day for the last umpteen years dealing with customers just like them.