If your P11 is like mine the reflective material flakes off the edges of the rear view. I also wanted to use a windshield mounting auto dimming rear view with the built in compass/temperature display. Instead of leaving an open in the headliner, showing the metal roof, I remix the bracket piece to allow re-mounting the factory trim cover giving it more of an OEM look.

I've also attached the bracket as just a more flush mountable piece if you just want something to cover the hole and dont have a trim piece to attach.