I like this idea, does it keep rain water from dripping down between your truck and the cleats?
My camper shell has rain gutters so any water that drips off the canvas makes it’s way to the gutters. However, there is a bit of sagging between tie down points (I just use paracord or bungees) and enough rainfall may overwhelm the gutters but I honestly don’t care, I can just shut side window.
If it gets crazy you can always pitch the canvas with the poles accordingly to divert rainfall.
I like it because it’s modular. I have another canvas that serves as a wall on either side and the materials are much more robust then the $1,000 awnings I have seen.
Add as many as you like and fold them up and stuff in a small action packer when done. Takes about three minutes to set up.