For those of you with the auto dim rear view mirror, this will probably be one of the easiest mods that you ever do, aside from changing a light bulb. I can't comment on the basic mirror. This is something I've been wanting to do for a while and I finally pulled the trigger. Why? Something is messed up with my navi antenna/radio and it thinks I'm at an angle when I'm not and isn't accurate. And I just like to know what direction I'm going. The mirror from a 2007-2010 Tundra fits PERFECT! No mods necessary, it's a direct plug-n-play. All functions still work. For reference, my car is a 2010 Prius 5 and came with the OEM auto-dim rearview mirror. Notes: You need the mirror with the BLACK 10-PIN connector and without rearview camera. Gentex model ZTVHL3. The compass letter colors match the color of the Prius instrument cluster. The OEM Tundra plastic plug cover is one single piece. The plastic plug cover from the Prius fits perfectly, even though it's two pieces. The Tundra mirror has an orange vanity light on the bottom that illuminates the Prius console controls. It matches the foot well lights and, honestly, it's not noticeable at all. So, if you're hesitant because of this, don't let it stop you. In the pictures I took, the light looks much more orange than it is in real life. If you don't like it, you can place a small piece of black electrical tape over the light and you won't even notice it. That's it!
I forgot to add: I would recommend doing a calibration procedure according to these steps: https://www.ttundra.com/2153/calibration.html
This is how I added a Homelink mirror to a gen3 with no switched 12v. Adds 6ma parasitic draw but has a on off button on the mirror for weeks long parking.