I love the compass/dimming mirror mod I put in my Camry, had to do the same in the Runner. Bought a new Gentex mirror for this model off eBay for about $64. Came with the wire, instructions, wire hiding tray, zip ties, all kinds of goodies.
You simply push up on the OEM mirror to remove it - no screw holding it. Next you need to remove the top console to fish your wires. Open the sunglasses case to access the two screws you need to remove:
Two clips are near the lights, just pull the console off and remove the one wire harness:
Next you need to remove the A Pillar cover. First pop off the tab that indicates the SRS airbag bu using a small screwdriver. There is a 10mm bolt under it you need to remove:
This is what the pillar looks like. The wire harness for the airbag and stuff is running down the pillar.
Pushed the wire for the mirror into the headliner and routed it over to the A pillar, then down the slots in the dash. You just don't want to put the wire in the slot the cover fits into. Run it down the hole the airbag wire harness is running down.
The fuse box has a blank fuse slot that gets power when the system is on ACC and running. I used an Add-A-Fuse tap into that spot, giving me power:
The OBDI port has a metal harness that has a hole. I used an M6 short bolt and clamped a ring terminal on the ground wire, then setup all that with a washer, bolt, and nut:
Tucked the wire all up, and VOILA - compass mirror:
The mirror has to calibrate so you drive in a slow circle. I wish the color was blue like in the Camry. Not a fan of the orange color, and it will not match my color scheme for LEDs I will put in there, but oh well.