Check out http://www.origamijeepproducts.com and look at the Origami Jeep Sleeper. Great feed back. It attaches to the back of a standard TJ and creates a sleeping area large enough for a standard sleeping bag and a full size pillow without removing the front seat. No modification to the jeep or tools required. It is origami; just fold up into a stack, 4” tall and weights less than 25lbs and fits neatly in the back of the jeep.