i have, it was a "console" that housed one 12 that went between the seats of a dakota i had, i never got it looking too pretty, and calculating volume was really hard, but i got it about right, and it sounded ok, i'll see if i can find some pics
that's where i'd get confused. I was advised at teh CRV forum to just fiberglass the bottom of the tub and have a MDF top. In my case, it would look good cuz of the MDF top (you won't see the fiberglass bottom) but I don't have any idea on how to compute for volume. the tub is a half circle on one side with straight sides and bottom. I'll try to give it a shot though. It's doesn't look like an easy build though.
thanks for the link. I'm trying to find a link on how to put carpet on a box. do you have that link as well? EDIT: I found the link: icixsound.com - Elemental Designs Teaches You How To Carpet A Box