Unfortunately I don't have a digital camera, so I don't have any pics, but for relatively little work I really think it really improved the appearance of the car, and probably saved a couple measly pounds... I always thought a Stang would make a better roadster than a family wagon!!!
I basically have one carpeted board replacing the back of the seat, and one carpeted board angled from the driveshaft hump to about 1/3 of the way up the backboard. I used self-tapping screws to attach the backboard to the top of the rear seat area (aluminum strip where convertable boot attaches), and I fabricated a bracket to attach the other board to the driveshaft hump, and then screwed the two boards together where they meet. (Sorry if that's hard to follow)...
... Basically the finished product looks almost like a nice custom sub box that follows the lines of the car... just that it's not sealed and doesn't contain any subs (yet)
I found it hard to find sheets of automotive carpet anywhere, so I first covered the boards with pleather... bad move- it scratches and tears easily. Then I ended-up ordering some sub box carpet from Crutchfield and upholstered the boards with that- much better!!
I think it was worth the effort...
-John