It's a sub designed for free-air, so it works well acting as such. It actually surprised me (and my co-workers) as to how well it sounds. Very good clarity (as per the design) and good enough SPL. Can't even see it without bending down to look inside the trunk. I have a piece of vinyl being made to cover it up from the inside (to maintain a clean look).

Notice the clamp. All I have to do is release the clamp and pull out the sub/mdf assembly to be able to use my pass-through (use it for my snowboard).

Next is a thin-type 16cm in the door panels. Should be able to mount them straight up :).