Every time I have to have the windshield replaced I just have them install a separate mount for the rear view as high up on the windshield as possible. That way when you move the mirror as high as the arm will turn it you actually have much better rear visibility. I still have a rear view camera running to my head unit at all times, but I normally don't need it. Been doing the higher mount since '05 and love it!
http://www.vehicross.info/gallery/sh...hp?photo=12101
Plus I am 6'4" and anything lower then that obstructs my view quite a lot. That is normally the first thing I do when I drive a car for the first time push the rear view to the ceiling, but with the VX I had to add another mount.