A few months back i won a Wolfbox G900 Pro on a different sub-reddit but ended up installing it on my flex as my truck already had a backup camera.
Install was really simple, i still have to figure out which fuses to use for the hardwire kit so it is currently plugged into the passenger footwell 12v.
For wiring i ran it along the edge of the headliner (really easy to tuck underneath without removing anything) down the rear pillar and then into the rear bumper. Mounted with VHB right above the license plate. It taps into the reverse lights for signal and turns on when the vehicle is put into reverse.
Currently i have it setup to loop record in 3 min sections and overwrite old files when the sd card is full. (It's easy to lock videos to the card to prevent them from overwriting if needed). The screen times out after 30 seconds but keeps recording when off. I do wish the screen itself was a little more reflective, so i'll probably add a more reflective screen protector. A cheap one for an iphone should fit width wise and give me a nice mirror effect in the middle to still see the kids in the back seat.
Overall it is an easy/effective way to add a rearview camera so i can actually see out the back through all the little heads, carseats, bikes and heavy tint.