Need enclosure volume ideas for 2 db4515s in sentra all seats removed but driver rear deck cut back to rear windshield. Electrical is straight running a salt4 and db aak4000 to 2 apocalypse db4515s. Looking to fill all available space from driver seat back but read windshield visible so height must be 22 max. Open to 4ths 6ths or high output vented. Thank you
