A few years since the last post, and this is my first, but thought it might come in handy. Fitted a reverse camera and screen to my FL2 today. Wasn't keen on removing the boot door liner, partly laziness, and partly didn't trust the plastic clips not to break.
I fitted the camera low on the rear bumper, one of the flush fitting push in types would work well, but I already had a little wedge type. On removing the rear light there is a route straight down into the bumper, so easy to send the camera power/video cable down.
The cabin is accessible from the gasket behind the light and by easing one of the plastic trims near the rear window forward (I was even lazier and used the vent behind the light, not really easier, just couldn't be bothered to go get a stanley)
Then it's just an easy run in the roof lining trim and up into the dash via the glovebox. I have the rustic edition, so a square cubby hole instead of a screen, so drilled a little hole in the side to feed cable in, and fitted a screen in front. Various places for a switched feed near the front if you had a screen with 'carplay' phone link, but most of the camera cables carry a live forward from the reverse switch, so that would power the screen and camera whenever you select reverse.
Using this route the cable supplied with the camera is more than long enough.
Hope this helps someone.