When we purchased our current 40' class A about 18 months ago it had the original backup and side cameras that worked sporadically, when it did function picture was dull and somewhat hazy as video output quality was outdated by today's standards. Considered replacing it with same brand installed by Monaco at over $1K, I just was not impressed with their current equipment offerings.
As most of us do, I went online to Amazon weighing the pros and cons of wireless and wired multi-camera backup systems. After reading hundreds of reviews on both wired and wireless versions I decided with the length of our rig I would take the extra effort to install a wired backup camera system. Although wireless technology is constantly improving many reviewers had problems with distorted images, total blackouts, and lagging video.
At 1/3 the cost of factory system I installed 4 HD cameras and larger HD display that has a plethora of viewing options. Although I didn't need this function, all 4 cameras constantly record video to an included memory card, might come in handy one day. I wired system directly to 12 volts, just press switch to view all cameras in whatever configuration we choose. While underway, monitor displays rear camera on top half and side cameras on lower half for 360 view.