I mounted a security camera on the back of my RV about 15 years ago.
The problem is they see things like you are looking out the window, not like you see things in your rear view mirror. In other words if there is a tree on the drivers side of your trailer in the back it will show up on the right hand side of your viewfinder. With a back up camera, the tree will show up on the left side of the screen if the tree is on the left side of the trailer.
The security camera will get you all confused until you begin to get used to it. I would recommend a back up camera, they are pretty low cost these days. I put in a wired camera in my shuttle van, and it has a 32 GB memory card, so it records the front and rear view all the time.
Check out this website,
AliExpress.com Search for back up camera. They sell just about anything you can imagine. Put in wireless. You might also want to power the camera with 12 volts, and then you can watch it from inside to see what is behind you, or watch from the cab mounted screen.
Good luck,
Fred.
