Carmax is a huge auto store. They sell mainly used cars that they "seriously check", but some of their locations in the south sell new cars. I bought mine from them about 5 weeks ago, and paid the extra rather then going through a private sale, because they said they "checked" their vehicles. I got about a block away from the place and the turn signal switch went bad (keep an eye on yours, the rear hazards will come on when you use the left turn signal, and it still registers that just the left is on when you use the signal). Got that fixed, and about 3 days later I had come up with a list of stuff that needed to be repaired. Engine needed coolant, engine needed power steering fluid, tires where very square, and my transfer case had developed a leak. Ok, so no problem, I got most of that fixed. All was good for about 3 weeks. Untill right as my warranty was about to expire, the front end developed a sporadic thumping and grinding (the griding mainly in slow right turns while going over a bump) and a severe pulling to the right. Back to the shop, and I went out there while they had it up on the lift, to find my right front aftermarket (and POS) front shock was bent. So two new front shocks and i'm back on the road again. And she stayed quiet for a couple of days. Untill I hit a pothole I couldn't avoid and now the thumping, grinding, pulling and shaking are back. (their idea of giving te front end of my car an alignment was drop my air pressure in the front tires back down to 25psi).
I've come to the conclusion that the tires are bad. If I had the money I would put some on in a heart beat, but no money. As for the thumping, I still have no clue, as it could be a number of things. And for the alignment, I'm going to do it myself.
Here is their website
http://www.carmax.com/
Sorry to sort of rant, but when ever people ask i give them my experiences. If they cehcked their cars a little closer, they might have happier customers.