I jsut did this a week ago...
The easiest thing was to pop the drivers side door foot panels out enough to run the wire under there and the driver's side rear side plastic panelwhich includes the rear most piller to the roof(only 4 bolts to remove this super easy)...I started at the rear of the car and worked forward to the dash..from the dash it tucked behind the plastic piece near the fuse panel and i pulled it through to the head unit slot with a fishtape (you could use a coat hanger)
In the rear hatch the wiring just went behind the plastic panel...I drilled a small hoe in the plastic handle from the bottom (so it cant be seen) and went up at an angle...I secured/sealed with rtv where i drilled the hole
My camera required taping into the reverse lights (which was super easy to do cause i pulled the drivers side rear panel above and had a connector about 3 or 4 feet from the camera end to a longer wire that went to the front of the car...I tucked all these in the headliner right near the rubber grommet in the pic above....
The only thing i could't do was get the rubber grommet for the tailgate out where wires ran through (also I couldn't get to the other end of the channel in the panel where the wires came out..its tucked behind other metal parts) so I pulled the weatherstripping up just enough to slip the wire past, put it back in place and ran the wire under there and zip-tied it to the outside of the grommet and covered the exposed parts in tape/tucked it down the inside sill to the plastic cover..this last bit isn't necessary a long term solution but its not noticeable visually ..when i have time and if anyone can update on a better way to do this last bit I'll redo it
this is the camera I used btw
https://www.amazon.ca/gp/product/B0744G ... UTF8&psc=1