We used to do something like this with my old FIAT station wagon and a canvas tent. We'd put a tarp over the gap between the lifted tailgate and the awning on the tent. It left sort of a carport between the back of the car and the tent.
The problem I see with the above SUV Tent, is that you need to go *through* the tent every time you want to get to the back of the vehicle. Consider how many times you do that during the day when camping, and decide whether you want to track through the tent when doing so. Just something to keep in mind.
I may end up with one of these.
I am going to be packing everything in cases, so it will be pretty easy to unload the rig, then set up the tent. Plus, I can still access the cargo area from the rear side doors. Honestly, the tent will hold most the gear anyway while the wife, dogs and I sleep in the back of the car. It will let me keep the back open to get more air in and keep the bugs out while the gear will stay "inside" out of the rain. It will also act as a changing room, so I'm not
too worried about dirt. Plus, when it is time to take it down, I can just dump any dust and dirt out the giant hole in the side of the tent.