Just got your message from a free wifi hotspot at Starbucks in Myrtle Beach. As far as I'm, concerned, it's basically a question of preferences as to placing it on the licence or on the grid.
Placing the camera on the A/C grid gives you an angle view compared to a frontal view when placed on the licence plate frame. By doing so it offers a better estimate of distances. You have to use additional bushings to obtain the appropriate angle. I still have some minor adjustments to do in order to .
We opened the roof cover of the A/C, drilled a hole on the left side and "fished" the wire through the rear speaker then through the rear lights and connected it to the back-up light. The holes as well as the roof cover were sealed to prevent water infiltration.
Now regarding the quality of the image, I'm satisfied. Since this is a wireless system, you can expect parasites from surrounding signals so when not in use, I disconnect the screen.
Hope this info helps you.
1998 Roadtrek 200 Versatile.