my car(a 2002 A3 1.8T) didn't had heated mirrors from the factory and from what I read it was just a plug and play job to upgrade to them. I checked to see if the wiring was present in the mirror casings and afterwards I ordered a pair of non-OEM heated glass, but after I installed them they didn't worked. I checked fuse no.1 and it was ok, but there wasn't any voltage coming to the fuse. I tested them in multiple days with outside temperature varying between -5C to +8C. The rear defroster is working. Any ideea what I'm missing? Should there be a relay for heated mirrors? Is an adaptation needed via Vag-Com(maybe for the Auto-AC; ch.46Central Conv. is not available on my car) ?