I can also confirm that this works and it shuts off, my mirror housing is huge as I have the assisted driving package but the clips are the same.
I also spliced into the same wire for my USB powered dash cam (because BMW still has not launched the drive recorder for my car). My dashcam is USB powered so I just soldered in a small DCDC converter on that line to go from 12v to 5v and soldered directly into the USB cable.. works perfectly.
Also confirmed with a multi meter that:
Red/Blue = +12v
Brown/Black = Ground
This is the DCDC I used:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1