I'm actually interested in that item now because it has most of the components to link up and the placement on bumper is ideal.
I have my camera on the inside facing down slightly from the rear middle break light trim.
This works really well and the camera does work without getting foggy or covered with water the only thing that's a con is when the rear screen is water covered.
This isn't really that bad tho I get good visibility even when it's raining.