[mlroman]

I'm posting hoping this will help someone with a similar issue and prevent numerous hours of searching through the internet with no results. I own a 550i Gt and have been fighting for many months with what I though was bad odor coming from the AC. Its a smell that I can only describe as being similar to a wet dog or dirty rag. After months, I finally discovered that it wasn't coming from my AC after all. I was sitting in my vehicle after a heavy rainfall one day and didn't smell anything at all even after having turned on the air. Upon opening the sunroof screen, not the actual window, I was hit with the smell. I closed it, the smell was gone after a few seconds. Opened it again, it returned. I started searching up in the sunroof and discovered a thick layer of mold looking gook alone the entire edge of the rubber that seals the sunroof glass. I cleaned this well along with everything else I could get my hands on, closed the sunroof all the way and closed the sunroof screen almost all the way. I left about 6 inches open, enough to get a good dose of Ozium air sanitizer in there and closed the screen quickly for an entire day. I must say that after a recent downpour, I no longer smell the wet dog smell at all.