I powered mine in sunroof area. I ran wire to left corner of windshield and use a visor mount. In order to tuck the cord under the headliner wrap a few circles of electrical tape around a section to make it thicker...it will then tuck nicely between the headliner and the windshield. I have had a hardwired RD since my first BMW in 2008 and this is the first time using the visor mount...by far, my favorite...no more suction loss....also, mounting under mirror seems to just be too much in the middle section of the window...visor mount also keeps it more out of view from outside the vehicle.