It was made using ½ MDF and cheapo auto carpet from Wally World. Here's the link to the original high res drawing of the speaker box with dimensions. http://i155.photobucket.com/albums/s281 ... Boxjpg.jpg. A couple of you asked for the original SketchUp file of the storage shelf. If you want this one to just let me know.
Measurements

Front

Side

Rear – The box is actually hollow with no bottom or back. I decided to do this to make it lighter and easier to access the components. The speakers are baffled with plastic Glad storage containers lined with sound deadening material. They have a thin strip of foam insulation around the perimeter of the container to seal it completely. You can also see the 1x2 I used to re-enforce the front and top panels.


Installed – I wanted to be able to remove it easily so the box is not mounted with any hardware. I guess you could mount it if you wanted but I found it stays pretty snug between the seat belt retractors.

If you need more detail let me know.
Rick