I have run a switched power wire from the fuse box, Up the a pillar than across the header to the mirror. This was a Nice professional way to install.I'm sorry but the old fashion mirror I have needs to be updated. My question to fellas is where would it be the most wisest to hook up a 3-wire auto dimming mirror in my 9-3 vert. I was thinking about tapping in the visor lights. Has anyone did this mod?