Today I installed a rear view parking camera and mirror/screen. Really pleased with the end result. The rear camera is mounted just above the number plate (time for a new number plate me thinks!).
The mirror turns into a screen when I put car in reverse, cool. The image from the camera has coloured lines to mark zones. I used a low kerb to check the distances with respect to the coloured lines and the red line is about 4 inches to the kerb. The photo is not as clear as in reality as I had to use a long exposure to get a half decent shot and not using a tripod.