HAving the face of the subs towards the cabin does not require u to put down the seats. i have about 5 cm between the seats and subs and they still kick the f**k outta me. But yes if u put the seats down it is a completely different story. They literally eat the air inside the car while the seats are down and are alot louder.

juss muck round with it and see how you like it try everywhere before you secure it down, everyones diff, if you don't want to fold the seat you can always extent the portholes(if any) with tubing to ure parcel tray. lets the air in.