The no haggle prices are bs. It's more like you pay what we say or kick rocks. They base the cars they buy off black book pricing for the most part and those numbers are way lower then the nada or kbb people use.
If nothing else figure what the car sold for new. Take the miles and the fact it is used and mostly out of warrenty and find a number you like. As the other guys said don't be afraid to say no or even to leave and think about it when not under pressure. I'd bet that less then 30 percent of people who leave without saying yes don't come back to the dealership. The dealers know this and most won't let you walk away without turning you over to management. Also known as a T/O