This is my current very rough sketch:

Squiggly lines would be where canvas goes.
-3/4in 4x10ft pressure treated plywood sides, square at the back and an angular front with flat faces. Bolted at the bottom to the metal rails of the trailer.
-4x5 door at the back that would hinge up so we could possibly hang a tarp around it have a very small standing area.
-3x5 angled piece of plywood at the front to give it some support
-1x2 ribs that would snap in place along the top of the walls with some sort of fastener so they could be removeable.
So with that I would have the skeleton of a teardrop, and then I would take some canvas and cut it to shape and it would be the roof. It would snap on along the sides, similar to this https://www.youtube.com/watch?v=Tpsd6-Sad-E
With this setup, the walls, back door, and front support would fold down and would only take up like .5x4x10ft and could easily be hung from the deck that the trailer is under. And the canvas tarp would just be in a closet somewhere.
So my question is, are there any glaring holes in this plan? Anything I am not thinking of? How would this handle on a highway, would the canvas hold up?
Would love to hear your guys thoughts on this!
P.S. Sorry if this is the wrong forum section for this!