There is a big markup on cars. Especially when you hit 40k. When car companies offer the employee pricing that's thousands off, they are still turning a good profit.
the "Invoice" and TMV are good starting points. Invoice is not what the dealer pays. I started with the invoice price from Edmunds, added the taxes and license and rounded the price. Then used KBB for our trade, and set a price for that.
They tried to get me to cave, but I stuck to my numbers, and they finally agreed. It may take a while, but if you don't let them rush or intimidate you, they will be the ones caving in.
Only after they agree to your whole numbers do you talk about financing, which I'd suggest already having in place. It's another good bargaining tool. They wanted our interest, so they actually beat the financing we had already acquired, making it an even better deal.
They finally even beat my offer by $100. Cars don't have set prices like other products because they can intimidate the buyer, taking advantage of their excitement and ignorance of what they should be paying.