Google "rooftop tent". There are several companies that make them. I always wanted to build a 4x4 camping trailer to haul gear and put one on the trailer.
Here is a link to one of the manufacturers.
Thanks! I found a nice one. Had no idea the price was that steep.
Its called a roof top tent. or RTT. lots of different companies make them, and they generally arent specific to any particular vehicle. Go to ARB's website and check them out.
The only hurdle with RTTs, once you pick one, is securely attaching it to a roof rack.
Thanks as well, I wasn't sure what to call them, I went around google looking for "car top tents," and that wielded little result.