ive got an 04 altima . with the seats up you can barely hear the bass, seats down its alot louder.after talking to a couple people in another forum i decided to try a 4th order bandpass ported through the rear deck with 2 4" aeroports. after cutting the holes and fitting the aeros in the deck,i havent been able to get a design for the box from anyone.i thought about just building a 4.5 cubed ported box with the subs facing back and ported into the cabin but everyone was saying thats a bad idea and it'll sound like crap. right now i have 2 12" re sex subs in a 2.5 sealed box that i was using until the box i planned on building is done, i tried facing the subs back, towards the seat, and up towards the rear deck and its definatly the loudest facing back.does anyone have an idea of what i can do to have it get loud with the seats up? if anyone's willing to make a design for a bandpass box for me ill pay for it with paypal.