If you have mold in the AC it's very likely DriveTime sold you a flood car. Not too surprising. These people specialize in junk.
Spend a few bucks for a Carfax report in order to confirm it on paper. If it shows up then you just need to start a private campaign of your own against the dealership. Looks for any areas within view of the dealership where you can park your car and place a large sign on it asking people to stop and ask about your DriveTime Lemon. If you can't find a spot just attach signs to your car and drive very slowly past the dealership, over and over again, for as long as it takes.
You only want them to take the car back, with no penalty to you at all. Don't back down, this is a winnable situation for you.