Got an OEM Toyota autodimming mirror for my 2015. Several mods to make it fit. The instructions say switched power is at the front dome light-checked not there only ground and constant 12v. Anyone know where to pickup switched power under the left side of the dash?

Going to pull the left a-pillar trim and run a wire, but color for switched power on the car would be helpful before tearing into everything. Worst case I tap into the power port, but ideally find something closer to the left side of the dash.

 

Accessory Positive Wire (+): Black
Accessory Positive Wire Location: At Ignition Switch Harness (White 8-Pin Plug, Pin #3)

or use remote line from radio harness to trigger relay for power pulled from elsewhere.