I took some pictures to better illustrate. While this is for the Z-Edge version I previously mentioned, most clip-on mirror solution will be somewhat similar in terms of installation.
It will likely have 2 lines coming out, one to power the recorder and monitor in the mirror, and another to connect to the rearview camera. I snake it under the headliner trim by the windshield, and down the A-pillar door seal as illustrated in the arrows:
The system comes with a 12v-to-usb adapter labeled with "1A" and "2.4A", and it doesn't say that it needs the larger one. There is a blue LED on top of the USB port array; not very visible in daytime.
But since I'd like to be able to close the sliding cover to that bin, I routed power this way:
Not on the USB port that allows for smartphone connection to the car UI though.
For the rearview camera, the line that provides power to it and signal back to the monitor gets snaked partially through the same route as power; along the top of the right side windshield behind the liner, down the A-pillar tucked under the door seal, but instead of turning under the dashboard towards the center console, it continues under the floormats and bottom trims of the B-pillar, snaking under the 3rd row seat on the right side, along the right side of the cargo area, up the liftgate seal on the right side, up the D-pillar trim, back into the headliner, and then out of the headliner to where the camera is mounted.
Note that you will need to account for the opening and closing of the rear liftgate when budgeting the line length. Having had installed this in 2 other vehicles (plus having had installed another different type before), and since I didn't have much installation time, I left it as a simple "slop" at the top of the D-pillar. The dangling wire can be seen. If I had more time, I would have coiled it like the line of an old telephone.
The system comes with long enough wire to route the line that connects the mirror and the rearview camera. I've tried a model with wireless rearview camera before in a smaller vehicle, but didn't have good luck with signal quality due to a variety of interferences. Wired rearview takes a bit more work, but will free you from any interference issues.