Posted in wrong forum originally.
Selling my X, I took out all of the stereo gear.
For sale is the custom one piece fiberglass box I had made. It fits like a glove and is TIGHT. The sound is great. It's dynamatted around the sides and comes with a JL 10w1 sub as well as the carpetted trim panel. The match is as close to factory that I could find. Price is $500 with the sub and trim panel.
This thing fits tight, you remove the relay tray, put the box in, then put the relay tray back. It uses every sq. inch of available space and does not protrude so you can still lift up the rear tray to get at your spare with no problem.