I retrofitted a backup camera on my Z yesterday. Was quite some work to pull out all the trim, but overall it's a straight forward job. I'd rate it 2/5 for difficulty
Only problem I have now is that the screen goes bad when I start the car or apply the brake pedal. Perhaps a faulty ground? Will try a new ground later today.
Some pics:
And a video:
https://youtu.be/61_oe8llSDw