Has anyone built an enclosure for an Infiniti G37?

So I'm picking up a G37 Coupe in the spring and I'm having trouble arranging the stereo setup.

Everything I've found on the g37 boards (myg37, 6mt, etc) has people purchasing the prefab custom g37 boxes from ebay. They are the 4080 (a sealed 12 in the corner of trunk with 1 cube) or ZEnclosure (a sealed dual 10" in the back of trunk with 1 cube). I found almost nobody that built a neat fitting custom enclosure for the vehicle. Ideally I'd like to do a single 12" ported, but the trunk seems to be brutally small so I'm not sure how do-able this is. I was looking at something like an Fi Q. Sorry for the rant, just wanted to see if anyone has done anything different.