When I fitted the reverse camera on my Peugeot RCZ I bought a replacement light unit with a built in camera which was meant to be compatible with the head unit and the car, it didn't fit. So I ended up buying the camera on its own and fitting it next to one of the number plate lights. All I needed to do was cut a small notch for the cable next to the lamp and the camera was screwed into the bumper skin. Yes, it wasn't central, but it didn't affect the display and wasn't that noticeable. Even the camera on My G29 isn't central.