I've got the Bose system in my 03 A4, it has the 6x CD changer in the double DIN head unit, all very nice indeed. Except, now the weather's getting cold, I've noticed that the left tweeter unit in the front door is occasionally cutting out/ crackles for a bit. It seems to be worse when the car is very cold - if you're in it for a while and it gets nice and warm with the heating, it seems to work ok. There must be a dodgy connection in there somewhere, any advice for tracking down the wiring? It looks like a heck of a job to even get the door cards off? Where do I start?