As the title says, I have an 09 M3 GT Hatch and I want to put my 12 inch subs from my 02 Sentra SE-R Spec V in there. Alpine says the required airspace is to be between 0.7-1.0 cubic feet per sub for a sealed enclosure. That means 1.4-2.0 for both 12's. My calculations for my enclosure allow me to still flip up my in-floor hatchback tray at the farthest back of the car. If anyone knows if this is true, I would greatly appreciate it. I just wanna make sure I didn't screw anything up. I used the Rockford Fosgate Box Volume tool on their website. I want as much room left as possible. PLEASE, can anyone confirm this?????