Ray, my truck is a Club Cab, not a Quad Cab, but here's what I did. Like you, I used the back seat primarily for "stuff". Since I'm single and I rarely had passengers in the back seat, I removed the back seat and built a shelf out of 3/4" plywood (3/4" may be overkill, but it was sitting in the garage, not being used). I made some brackets (out of 3/16" thick by 1-1/2" wide scrap steel) that are bent at about 75 degrees, and bolted them to the floor of the cab using the 4 seat-mounting bolt holes. I then bolted (w/lag bolts) two 2X4's to the brackets, sticking straight up, that are about 4" high. Then I laid a 2X4 (that is the width of the cab) on top of the uprights and bolted it down. I then attached the plywood shelf to this horizontal 2X4, using hinges, so I could tilt up the shelf from the front to get under it (the hinges are mounted on the back edge of the horizontal 2X4). The shelf is covered with foam rubber and a leftover piece of household carpeting. The carpeting is folded over the edges of the shelf and stapled to the underside of it. I have a pair of subwoofer speakers that are in boxes under the rear seat, so the front of the shelf is simply resting on top of those boxes. If I didn't have those boxes, I would have attached some legs to the shelf and had them rest on the surface that the seat normally rests on.
The shelf runs from the very back of the cab to about 1" from the back of the center seat/console. The height of the shelf is about 7" below the height of the center console lid. The great thing about this shelf is that many things are now within reach while I'm driving, such as CD's, MiniDiscs, mapbooks, a jacket, trash can, paper towels, etc. When I go camping, I put an ice chest on the shelf, and various food items ("road munchies") in a cardboard box within reach. Many times I have cleared the shelf and slept on it in a sleeping bag. I'm 5'9", so I can't quite stretch out, but it's okay for a night or two.
I also screwed in small eyelet screws along the rear of the shelf (right through the carpeting) to use as anchor points for bungee cords to hold the ice chest, cardboard boxes, and small trash can in place. I installed two large hooks on the underside of the shelf, near the front edge. I store my removable CB antenna on those hooks.
This shelf is not the fanciest thing around, but it didn't cost much to make it. The beauty of it is that I can remove the shelf and re-install the rear seat in a matter of minutes. All I have to do is remove the 4 seat mounting bolts that are holding the brackets down.
I had an idea to make a front bulkhead (with holes cut in it for the subwoofer speakers), so that stuff could be stored under the shelf and not slide forward every time I hit the brakes, but I never got around to making it. If I was to ever do this project over, I would cut the shelf in half (or even into thirds), so that each side could be tilted up individually to get access underneath. Then I wouldn't have to empty the entire shelf before I lifted it up. Another idea I've kicked around is to cut out a hole in the shelf and sink an ice chest into it. It would be a whole lot easier to reach for a drink while driving if the ice chest was sitting lower.
One more thing: Dodge doesn't put any carpeting or sound deadening material on the back wall of the cab behind the rear seat backrest. I put some insulating material on the back wall, using weatherstrip adhesive, and then covered that with more of the same carpeting I used for the shelf. I got the insulating material from the J. C. Whitney company.
The height of the shelf could be made higher or lower. Due to the height I have mine at, plus that it runs so far forward that it's within an inch of the center seat/console, I can't recline the front seats very far. No big deal for me, I almost never do that anyway.
Hope this might give you some ideas to start with.
Andy
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