2 FI Q 15s in ported or sealed box

Hello, i want to build a box for (2) FI Q 15s, here is the size of the area i have too work with

WIDTH = 32 INCHES

HEIGHT = 18 INCHES

DEPTH = 29 INCHES

I will be able to add height to the box if I shorten the depth

for a sealed box i can use the cutout sheet that FI recommended at 2.5 c.f., i'll just build two seperate boxes then just bolt them together.

now for a ported box i have no idea what volume or what to tune it to??? i listen to metal, rock, country, blues,everything inbetween, but i don't listen to rap.

FI specs for a ported box is 2.8 - 4 cu. ft. and use 12-16 sq. inches of vent area per cubic ft. of volume.

i would like a box that would not be too boomy, i like the sound of a sealed box but would like the extra output of a ported box?

i dont know if i have the area for a ported box? if someone could come up with a design that could fit that would be great, I also would need a cut out sheet for the ported box, well thanks alot for any help or ideas......................... thanks Brian

P.S my car is a 1996 honda civic hatchback.