Hell I would never use that. Looks almost as annoying as a fiberglass cover that usually always ends up in your way or making the bed useless.
Rear view camera for the trailer is a good idea.. Seeing as we are delivering and towing different RV's every day.. Would be a big hassle to mount and set up a camera for each one.. But our trucks have towing mirrors and such too.
They do make wireless ones where the camera has a magnetic mount so you can remove it from trailer to trailer. See them on ebay all the time.