I had done the same thing that kvo had done, but the other day I tried a few different things, and now i have sort of a better place for it. Well I stood the tire up, and I put it on the pasenger side of the cargo area, right over the 2 tie points on the floor. I then got a Ratcheting tie strap, and attached it to each tie down point and up over the tire. cranked up tite, and I now have a new spot for my spare tire. If you do this you may need to place some rags where the tire comes in contact with the plastic interior panels. I have a piece of webbing tied in a loop and hooked onto the front most tie down and then the tire kind of goes in the loop, and the tie down strap attaches to the loop at the top of the tire. The purpose for this is to push the tire towards the front of the truck more(to stay away from the rear hatch).
This weekend I hope to have a Spare tire mount made for my truck, Next week I hope to have photos of the finished product.