Condensation may develop in the heater case which can cause a musty odor from the heating, ventilation and AC (HVAC) system. Our technicians tell us the drain system should be checked for debris. In addition, a cleaner is available for the heater case.Google+
Car Problem Reports
Volkswagen Rabbit Odor from HVAC vents
Volkswagen Rabbit Problem
Average Mileage: 43,500 mi (40,000 mi - 50,000 mi)
Visitor, 2007 Volkswagen Rabbit, 40,000 mi
Bad odor when I use the Conditioner.
Visitor, 2007 Volkswagen Rabbit, 50,000 mi
I had a similar issue and found that a cabin air filter replacement seemed to do the trick.
Visitor, 2008 Volkswagen Rabbit, 44,000 mi
musty skunk odor when ac has not been used in a while