Originally Posted by spearfish25

I've looked into this. I think the wiring is there. Even if it's not, you can tap the heated mirror into the mirror adjustment circuit and just let them stay warm all the time. Frankly, that would be better than having to turn on the defrost (my older Audis had the heated mirrors all the time). This would keep the mirrors clear when you go from outside into a warmer parking garage, which is a prime time for my mirrors to fog.

Replacing the mirrors costs about $350 per side if ordered through the dealer. So I bailed on the idea.