pamdunk

I meant to say, Yes the cabin filter has been changed. I think my car is due for next service soon, I will definitely confirm with them if they are putting in a new cabin filter.

Thank you Garret and Trevor. Has the filter has been changed. As per the service dept. at the Audi dealership I go to, there is typically a residual fluid when a/c is used. This area is hard to reach and its recommended that a professional should clean it up. The other solution they recommended was to leave the fan running without a/c for about 5 minutes before i turn off the engine. I will try the smoke grenade type cleaners if that helps.

I have an A4 since 2014 and I have had this foul smell when I turn the A/C on. This started happening after a year or so. The Audi Dealership service people told me that when a/c turns off there is some residue left and it stays there. Next time you turn the a/c on it remits this foul smell which is hard to bear. They said they know about this issue and it will cost about $300 to clean that area, which is ridiculous. Why would a luxury car maker have such an issue in the first place. I have cars from other brands and never experienced this. Any tips/suggestions on how to get rid of that smell?