I have my box leftover from selling my JL 12W7's and want to get rid of it. It's in very good shape and was professionally built to spec for me, tuned to JL's recommendations. It's a monster of a box. If you have a WRX/STi don't bother unless you want to remove your trunk lid just to install it (and I'm still not sure it would fit).
The dimensions are :
17" tall X 30 1/4" wide X 24 1/2" deep.
It weighs 90 pounds and is constructed from 3/4" MDF. I had the box sitting with the subs firing up. Ported using (IIRC) 4" or 5" rounds.
Pics coming soon.
This would cost a pretty penny at a local shop. Asking $100 picked up. Trust me, you don't want to pay for shipping on this.