What you will need:
3 4x8 Sheets of 3/4 in MDF.
1 1/4 in sheet of masonite
52 x 26 in of Carpet ( color and style is up to you)
Access to a Shopbot or any CNC router
1/4 in router bit
1/8 in router bit
1/16 in drill bit
square drill bit
6 x 1 5/8 square bit trim screws
3M 74 Spray adhesive
" shit house" latches or swivel latches ( the guy at the hardware used the first name, amazing)
Two 6 x 5/8 in hex head bolts.
Step 1: Measurements
What I did was take the width height and depth measurement taking into account the angle of the back row of seats to see what the maximum space was we could get out of the container.
One thing to note is that in the new expeditions the rear door has an automated pneumatic arm which travels about 3/4 on an inch to the right as it shuts. The files I have layer out here account for that travel, but should you decide to change or adapt the designs, keep that in mind.
The final dimensions were 49w x 18 3/4h x by 23 3/4 deep. This maximized the bed space while still allowing for items to be placed on top.
The next step was to remove the two plastic brackets bolted to the sidewalls. These are in place to hold the fold out shelf built into the base of the trunk. Make sure to save the parts should you decide to remove the container in the future, but for now you won't need them. These holes will serve as our anchor points for the container in the final steps.