This is mine
Its a Napier Sportz 10 x 10, 7 feet high inside, the boot will fit around a 17 foot circumfrence
The boot will zip off to use it freestanding
They are not cheap though
http://www.sportzbynapier.com/suv_minivans.html

The boot will zip off to use it freestanding
And there is a wall to zip up when not attached
They a re nice though, Wish the screen room and rain fly were an option when I bought mine

Little better look at how it attaches on a truck
The black straps are sewn on and a webbed material like seat belts, they have cinch buckles on them to adjust the circumfrence

First time we used it, I set the tent up, back the truck into it, then we unloaded.
A little while later the peeps started comin round for the tour. The girls next door went " COOL, The truck puked in the tent " Becasue they saw no gear except the tent come out of the truck