Anybody know this answer? I have a 2000 A6 with the 2.7. It has heated seats in front and rear. How do you know if the side mirrors are heated? They are yellowing too. The mirrors don't have any wavy lines, but don't know if that model/year had them.

 

My son has same car & it hadheated mirrors. The brown liquid that is sandwiched between glass & mirror eventually leaks out & causes poor reflection. I removed mirror glass portion from the mirror mount & meticulously cut the sealed plasic rim between the glass & the mirror. Cleaned the remaining brown stuff from both the glass & the mirror, & resealed it using black silicon. I left the rusted heater wire disconnected & taped off. Reflection is much better than before. Don't have much need for the heated mirrors down here in S.Fla. It was 84F today!