Have an autobahn mirror that I just got.. and I am loving it.. its stunning to see what I couldn't see before, and night vision is excellent, even like it better than the external mirror at night... 

I've attached the mirror to the frame that runs vertical and seperates the front roll up window from the front push out triangle window, it's placed six inches down from the top of this vertical (black) frame (whatever its name is), and this is measured from the front edge of this frame and not the back of this frame (top is angled, back edge is 6.5 inches... )

The top of the autobahn mirror is level with the top of the external mirror