I've had two replacements on mine and in both cases they came with the mirror mount bonded already and also the auto headlight/wiper sensor mount bonded.

The critical bit in my case was to get the right screen. I have the 'Climate Comfort' screen and it comes in two versions where the auto wiper/light sensor mount can be either rectangular or with rounded corners. The actual sensor unit just clips into it's mount and the mirror clips on too.

Whatever you do, do not allow the fitters to scrape the old mount off the old windshield and try to attach it to the new one - it will never work as the bond MUST be optically perfect.

I had two OEM screen used as the car was still under warranty and BMW GB refused to honour the paint warranty if a non-OEM was fitted, or was fitted by anyone other than BMW themselves. Insurers were happy with this and paid up both times.

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Me:
Current: 2011 E71 40D Vermilion Red/Beige Nappa

Wifey:
Current: 2012 R80 Countryman SDX Green/Cream