Under that Regulation 109, the line:"To assist the driver to see the road adjacent to his vehicle" seems to me to sum up what a rear-view camera is all about. After all, "adjacent" covers all parts of the road, including that part immediately behind the vehicle (and, by implication, the vehicles on it). You are not supposed to do what I can do, which is to look at the CCTV camera images (garage forecourts, shop interiors, home security ) which appear on my "spare" wireless channel if I select it while driving. (I only do it when parked, honestly!) Actually, I have a wired camera on the back of my tow vehicle, plus a wireless receiver in the rear offside; the caravan camera is wired to a transmitter fitted in the offside of the front locker 5 feet from the receiver, so no connection problems, and no wireless interference over the 35 feet from camera to monitor. I can select the appropriate input on the monitor. External CCTV signals are too weak to overcome the caravan transmitter when it is switched on (remote switch, not in gas bottle locker).