A closer look at the rear view mirror revealed a plastic tunnel running from the mirror to the overhead panel where the OnStar/lights/HomeLink controls are. Inside the plastic tunnel is a black cable coming from the mirror I'm thinking that the Blackvue recorder wire could be routed through the plastic tunnel (it's plenty big enough) and into the overhead panel. Surely there must be several places inside the overhead panel to tap into 12v switched or unswitched power. Has anyone taken off the overhead panel and could share how it is done? I have replaced the 3 light bulbs with LEDs but that only involved prying off the clear light cover.