My Rear Cam is bolted to the rear parcel shelf and the cable runs across the shelf, down behind and under the offside rear seat, down and across under the rear floor mat and up into the USB socket on the central cubby box.
If I need to take out the parcel shelf for any reason then the cable simply unplugs from the camera.
The camera needs to be towards the bottom of the screen, to ensure that it is within the wiped area of the window wiper.
I was concerned about the shock loading on the camera, if mounted to the rear screen itself and subjected to the slamming of the boot lid and of course it is easily transferred for car to car.
