I currently own a 2009 Malibu - this is the 2nd Malibu that I have owned, my last car was a 2005 & I had the exact same problem. My AC smells horrible - it smells musty and has a bit of a vinegar smell. This is EXTREMELY embarrassing to have anyone ride in the car with me & VERY frustrating that NO dealership will do anything more than spray Lysol in the vents & tell me to do the same. This does not FIX the problem, but masks it! There has to be something done about this. I have looked on the internet & see that several people have the same issue & it is even happening on the new Malibus. I need to have something done to fix this problem ASAP. I usually buy a car every couple years & I prefer Chevy over any other make, but I will not buy again considering the lack of response I have received from Chevy.