Sybesma's Electronics at 581 Ottawa Avenue # 100, Holland, Michigan.

I own a 2002 BMW M Roadster and the auto-dimming mirror developed a slow leak of the electro-chromic fluid which created a bubble. A quick web search lead me to Symbesma. The service was quick, inexpensive, and very responsive. I had my mirror fixed in under a week and it works perfectly.

A couple of things I should mention:
1) if your mirror starts to fail, removed it immediately as the fluid can corrode your dash plastics. I will describe the process below.
2) use tape to seal the edges of your mirror before shipping and wrap it in a towel in case it leaks. If it leaks the shipper will be obligated to open it using hazardous materials protocols which means you'll lose your mirror.
3) send it overnight or priority mail to minimize the mirror's exposure to temperature and air pressure differences that could exacerbate any leakage.

How to remove mirror (see photos)
If in doubt take a photo of the mirror before each step as a visual record.
1) tilt mirror downwards
2) use finger to gently lift panel on the attachment "stalk" off
3) put the panel in a safe place!
4) unplug the mirror (the toughest step)
5) GENTLY apply firm, steady, slow pressure as close to the windshield as possible and rotate COUNTERCLOCKWISE about 30 degrees to release the mirror.

Very fast and great customer service!!!! I had my rear view mirror repaired and the price was reasonable compared to buying a new one.