I've been meaning to post about this, but I only think of it at night. My '06 Prius has the rear-view mirror that auto-dims when there are car headlights shining in it at night.

The problem is, the mirror doesn't seem to work very well and frequently the mirror seems as if it's not dimming (or dimming so little that it isn't noticable). I'm not entirely certain why this is -- sometimes it works really well. My "theory" is that the rear hatch has the mini spoiler on it -- which obstructs *some* light. Depending on the height of the headlights of a car behind me, perhaps this is enough to block the glare of the headlights from the mirror's sensor, but I still see the glare.

Anyone else have this problem? Any suggestions to fix it?

Attach a transparent blue piece of plastic film over the front sensor of the mirror. This will trick it into dimming darker as it senses it as if it is dark outside. When this front sensor on the mirror gets more light, it does not dim the mirror.

Yep.. turn your mirror upside down!


I have mine upside down and no one really noticed. That way, the headlight sensor is up on top near the ceiling so it's out of the way of the spoiler. Now it dims like it should.


Just a word of caution. Take care when rotating the mirror. Make sure the wires behind it aren't bent out of proportion or tangled.

Mods: EV mod, VVT-i emblem, sport pedals, OEM cargo mat, JDM Prius interior footwell lighting, Sylvania Silverstars 9003ST, DICE iPod kit, OEM all-weather mats, TomTom ONE v2, LED licence plate lights.