91 nissan 300zx sub box for 2 12's

I have a 91 nissan 300zx 2+2 and if ever seen one hatch space is minimal and odd shaped.Am wanting to put two 12" soundstream T5-12's in. i also have 2 soundstream pcx1000d picasso series amps to power them with. amps are 1 ohm stable and in excess of 1000 watts. want to face subs forward and under the hatch overhang if possible. subs require 1.0 cub ft of airspace per sub. am looking for any ideas in how to do this. if anyone has ever done one? is fiberglass my best option or... height from hatch floor to rear hatch is 11"

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