I had one on a Toyota Tacoma for over 10 years and my buddy had one on a gmc full size truck for along time. They are good shells if you can pick one up in good condition for cheap. Basically you can use the shell as if it is a normal topper/canopy when not using the tent, then when you want to sleep in it, the tent just pops up and over to the side. They are kind of like the FlipPac but usually way cheaper due to their age and no longer being made. Just make sure the canvas is good and that all the hardware is functioning. There use to be, and might still be a website that had used wilderness shells
for sale as well as people hunting for one to buy. If the website is still current it would give you an idea of what they are worth, which is usually about 500 to maybe even 1500 bucks. Good luck