I just got my SP4 yesterday and I'm looking for some advice. I can fit a ported box, roughly 4.5 cubes, in the smaller section of the trunk closest to the seats. If I do this, there will not be much (if any) room left around sides and top the box. Will this be OK for for rear firing the sub or should I make the box longer with less height? I have a car seat in the back most of the time so having the seat down isn't normally an option, although I guess I could move it to the side. If I front fire the sub with the seat down, is there anything else I should take into account? Or would top firing be an option?