Ok, the things you will need are:
1 Staple Gun w/ staples
1 Carpet Cutter
An amount of automotive carpet. (I used a 6'X4' piece and had lots left over)
1 piece of MDF or ay other sturdy piece of wood. Plywood may not support weight.
Lots of peel and stick velcro
1 circular saw, bandsaw, or jigsaw
1 48" length of 2x4.
1 bottle of carpenters glue
2 clamps
Ok, to start, I will assume that you have already removed your back seats and any unnecessary back seat hardware. I left my rear seat belt straps in, just in case I decide to go back to a 4 seat configuration.
First, you have to cut the board to the right dimensions. I used a circular saw, but a bandsaw or jigsaw should do it. The dimensions for the board are shown below. Be sure to test fit the board in your car to ensure it will fit before carpeting!
Once that is done, you need to cut the automotive carpet and staple it to the board. When I cut the carpet, I left it about 3 inches long on all sides so that I could fold it over and staple it on the underside of the board. USE LOTS OF STAPLES!!!
Next, you need to create some blocks to prop up the front end of the board. Cut the 2x4 into 4 12 inch lengths. Glue one piece on top of another to create the first block, and then do the same to create the second block. You may wish to clamp the glued pieces together overnight to ensure that they will not come apart. When the blocks are dry, carpet them with the leftover carpet.
Then you will need to run a pice of carpet along the back of the rear seat area under the lip where the trunk area ends. I used peel and stick velcro to attach the strip to that area. This step is not necessary, but gives the car a cleaner look. You'll see what I mean when you do it. If you sjip this step, there will be a gap between where the board sits, and the lip of the trunk area.
Next, put the carpeted board into the back seat area. Make sure it sits on those U-shaped metal things that are welded to the bottom of the back seat area and is pushed back as far as it will go.
Finally you need to put the blocks in. Put them on the front edge of the board as shown in the diagram below. They sit nicely on the level edge at the front of where the back seats used to be.
Finally, I attached the blocks to the underside of the board using more peel and stick velcro. It's good because it makes the board easy to remove if need be. The finished product is very sturdy and does not rattle at all. PM me or post with questions.
Finished Product!