The rolled up "kit".

- Rollup
The kit rolled out.

- Rollout
Inside the rolled out tarp roll-up.

- The kit contents.
Bungee loops attached to roof rack.

- Hooked up to roof rack.
Sagging bad because I didn't really tension the lines.

- View from the front.
Plenty of coverage for ingress / egress from the side door if sleeping inside the truck.

- Broadside.
It certainly isn't fancy, but it does what I need it to do.
If you wanted it to be more rigid, and didn't mind it being less compact, you could add pvc pipe to the sides and front pretty easily and it would still roll up and be able to strap it to the roof.
Pardon the sloppy pics, I just threw it together while the kids were entertained between dinner and bath time.