I looked into getting the Advanced Car Eye a while ago, and I decided against it -- mainly because
the reviews for their app are pretty horrible.
I ended up getting a BlackVue 4K camera and I've been pretty happy with it. If you do end up buying one and taking it somewhere to get installed (which I would recommend because the trim is a pain to do), make sure to print out the
fuse card from the BMW website and bring it with you.