In my 2013 Kia Optima EX - my mirror will tint depending on how bright the lights behind me are. I want to disable this but I don't see anything in the manual except "Press The Power Button" which is fine - but every time I turn on my car it default to the "On" state. Is there anything I can do about this?
Another thought is this, the way these rear view mirrors work is it has sensors back and front in the mirror which detects the difference in observed light. When the one behind (facing you) detects it is brighter than the front, it will dim the mirror. Covering both of these will make the mirror "think" there is no difference in observed light and will always keep the mirror the same without dimming. This would also allow you to change it back fairly easily. Black electrical tape placed in just the right locations should do the trick and should be a low observable to anyone else in the car unless they are really looking for it.