@r1200gs4ok, While you are wiring you might want to think future proofing. Extra cameras. (I wish someone had mentioned it to me.
Here's some Blackvue unique ideas for you.
1. Look on something like this on Amazon
Blackvue Pigtail will provide power and save you from cutting up the Blackvue power cord.
2. Here's the
Interface cable to tap easily tap into power behind the speaker grille. (You have no idea how far we came to find these connectors and make it easy to install the dash cam. whew)
3. You do not need the 35' cable to the rear that comes with the Blackvue kit. Its too long. Use this
20 foot version. Works great, 15 feet less wire to have to hide.
4. I first installed one Blackvue 2CH camera (front and rear windows). Then had a brainstorm. I bought another Blackvue and mounted them (of course I needed more cable) different. I mounted one's Primary in the front windshield, and the Rear - not in the rear, but in the left quarter window on the left rear seat. And the other 2CH camera, the Primary in the Rear liftgate window, and the rear camera in the right quarter window on the right rear seat side This gives me 4 cameras and 360 degrees of coverage. I used a couple of my local Tesla club decals on the quarter windows to conceal the camera lens, so it goes unnoticed by most people.
I don't think anyone had reported doing 2 2CH cameras before. I wished someone had given me the idea when I was running and hiding cables. Would have been more than 50% easier if I had been doing all three 20 foot cables and running power one time instead of multiple efforts. You can tuck the cable from front to left quarter window by in the headliner. On the rear - the liftgate glass, its cleaner but more difficult to run the wires through the trim and the black rubber boot into the body and over to the right side C pillar. to the right quarter window.
There's many videos and articles written to guide you for dash cam and Blackvue dash cam installation. Use them. If they don't one last thing, don't run your wires along the left C Pillar. We've learned. There's car antenna wires there. They will interfere with dash cam signals.