You need to disinfect the hell out of the HVAC system, it sounds pretty nasty! Mine was the same, it really sucked - I know how you feel. Grab a few dozen cans of lysol and go here:
http://forums.genvibe.com/zerothread?id=19575Replace your cabin air filter too... And once you finally get everything cleared up, always remember to turn off your A/C when you're ~5 minutes or so from your destination - crank the fan all the way up after turning it off so your evaporator and whatnot can get dried out. If you leave the A/C on and park the car, water is going to become stagnant inside your dash and things will get moldy... Not letting that stuff stay in your car is key, I learned the hard way. Now without even thinking about it, I'll kill the A/C several miles before I get to where I'm going, the car never gets parked and the engine shut off with the little A/C light lit. It's working quite well, no nasty stench at all from the new car. The dealer can also do a thorough cleaning, I had to have that done on another car I used to own. They'll take everything apart and use some special stuff to help kill all the crap that may be growing in there...