Thought this would happen at some stage, think one of my heated door mirrors has failed! Driving home from work last night (ambient temp 15-16 degrees C according to dash display), typical wet early evening, I noticed that neither of the door mirrors cleared themselves, but I thought on my A4 they were heated whenever the ignition was on (they were on my '94 80 Avant)? As an experiment I turned the heated rear window on and after a trip of about 5 minutes got out and felt the mirrors, o/s felt warm but n/s was stone cold...... Does this mean the mirrors are heated only when the HRW is on? Looks like a new mirror glass is needed but would sure like to know when the mirrors are meant to heat up! Thanks.