You can install awning track on the side of your van! van dwellers or those new to RVs often do not know about this product. You can even get it in white!
To hang a tarp or shade cloth get some 3/8" poly tubing from the hardware store. It is sold by the foot in the plumbing section. that tubing fits inside the track and glides along easily.
I cut the tubing into 1" lengths to make my own shade cloth hangers. Thead polyester Paracord through the tubing. Needs to be polyester as it is UV resistant (nylon is not UV resistant, it won't last to hrough the years). At the other end I put the cord through a washer. The hole in the washer needs to be just large enough for two ends of the cord to pass through. Then tie an overhand knot to keep the washer on. The outside diameter of the washer should not be able to pass through a grommet that is on the tarp, shade cloth, shade sail, etc.
With this system in place you can quickly install and remove your shade cloth in a few minutes time.
Awning track is available in 8' and 4' lengths. Just be sure to carefully line up any joined lengths so the tube slides smoothly.
If you want a waterproof cover you can purchase sewn on strips of "keder" heading and use polyester awning fabric. the Sailrite website is a good place to purchase the keder track headers.
I will post some photos in a few weeks when I have more time for that.