As far as I can tell, the auto dimming mirror also houses the compass sensor, that bulge behind the mirror. On that bulge is a button with a hole in it, that points upwards, right behind the mirror. At night with the dome light on to activate the dimming feature, it seems to me that clicking on that button adjusted how much the mirror dimmed, I think about 8 clicks to where it cycles back through from brightest to darkest. It's been a while since I,ve done it, so can't remember exactly. Seemed to work for me, but I still have issues with the dimming of that piece of cr...! I also did the 180 flip. Ray