Mirror (glass only...not entire assembly) looks like it "overheated" (a section of glass is missing). Could it be possible that it actually did overheat? If so, does this indicate the need to replace the entire assembly? Or is it possible to replace just the glass/heater? Also I would just like to thank you all for your posts...I have great success following some your advice including cleaning the IACV and changing the top drive belt...any suggestions regarding parts and/or replacement procedures would be greatly appreciated. I will try to post an image of the mirror.