I got a box I built today, It is for a 12" shallow mount subwoofer. It wont fit behind my backs seats. I built it about 1.5 inches too talland an inch too thick at the top, so my back seat wont close back all the way. So now I have to rebuild the entire thing, because it would be easier to start from scratch. If I decided to modify what I have I would have to take it all apart and rebuild the front to recenter the subwoofer hole. It is 30" wide 15" tall 3.5" at the top and 5.75" at the bottom, .75 cubic feet of air space. even has a recessed area for the amp to mount into to save room. pm if you know anyone one or if you yourself could use it. Otherwise I'll just throw it in the trash. Thanks