two 15s with limited space

I need to make a sub box that will house two 15s (mtx thunders 6000) but i am limeted to space. i already have them installed but am trying to free up trunk space.

i found this to help with selecting the right volume but i am farely new to boxes and volume size and there is some things i dont understand like spl.   http://www.mtx.com/caraudio/products/manualsQuickInstall/subs/Thunder6000Ref.pdf

if anyone could help me figure a out a box design that wont destroy my subs but will free up trunk space that would be great. ive got about 10" of top to bottem trunk space and 32" wide. car is a 2002 acoura rsx

You can see, the SMALLEST enclosure would be a sealed one. For 2 15's just shy of 4 cubic feet.

In a nut shell.... say bye-bye to a great deal of your trunk. Your box (with the given dimentions) will need to be at least 20 inches long.

Give some REAL thought to a smaller sub(s)