My family, friends and I have dealt with two local Carmax dealerships several times over the past few years. They've never given us any BS whatsoever. Mostly, we've gone there to see how much they'll buy our cars for and their prices have been very fair, sometimes much better than expected. And of course, much higher than what the dealerships will give on a trade-in. And they never pressured us to buy a car from them, even after having test driven a few.
Carmax has been the best experience we have had dealing with dealerships, aside from once going through the internet sales department for a local Toyota dealership. In that case, all the details were worked out online and we went in, signed the paperwork and were out the door in under thirty minutes.