I hope someone can help me! (My car is a A3 TDI 2.0 R4 on a 54 plate) I recently had a strange smell comming from my air con. So I took out the pollen filter and used a foaming air-con cleaner to clean out all the vents etc. Then of course I replaced the pollen filter and put it all back to how it was. Since then I have heard a strange popping noise from the front....on further inspection I got even more confused because I could hear this even with the head unit switched off!! So I took out the head unit and pulled the plug on the front speakers which has eliminated the "popping noise". All I can think of is when cleaning the vents either side of the centre speaker I have damaged or disturbed some wiring.... If anyone can shed some light on this any help would be appreciated. I presume (considering the front speaker plug on the stereo has four wires (front left & front right) that the wiring is split somewhere else to go to the front tweaters & centre speaker? and do they go to a seperate amp for the front? The next thing I am going to try is to disconnect each speaker in turn to try to find out which one...but i'm unsure if its a speaker or some wiring that has been disturbed near the blower motor.