I will answer my own question and maybe it will be useful for someone else. The wiring to the mirror is switched. It is timed just like the Aux port. It turns off in about 6-7 minutes after you shut the car off and lock it.
Anyone looking to install a mirrortap here is a good guide on how to do it. The fitting of the leads is not as tight as I would have liked it. It had to be secured with electrical tape to keep consistent good contact but it works.
https://f90.bimmerpost.com/forums/sh....php?t=1556366