I have an old box in my attic that came out of my 99 ext cab (many years ago). It's a Pro-Box pre-fab, holds 2-10" subs downward firing into the floor, under the rear seat. If anybody wants it, come get it or I can bring it to the track sometime. I didn't like it cause you were limited in the type of subs you could use cause it wouldn't hold the deep style 10's.

What the hell, it's free.