Ok, let's see if I got this right. My design and bad model building ...
First up the drawing
This is the cardboard frame. notice the fold out wings, which will give me somewhere to put dirty shoes, radio, light, etc.
The back view of the trailer with the fly open.
What it will look like closed.
I plan to have a tarp that will stretch over the top and back to keep rain out of the back, you may have noticed the two "poles" at odd angles in the frame picture. Still working on that one.