ported box design need advice

i have 4 pioneer 3002spl 12"s and am trying to build a box in the trunk of my 300c with the speakers facing up and the port facing in the cabin from where the seats fold down it would be 2 seperate chambers 2 speakers each chamber and dimensions are 30.75" wide by 31.5" length and 15" tall after subtracting wood

box volume is 8.40 ft^3 net

speaker displacement is .084 each  total .336 ft^3

after subtracting speaker displacement i should have 4.03 ft^3 for each chamber

now i need to know using square ports what dimensions the ports on each side should be length,port area etc.

please help someone

ghettob, if you open a space from the trunk to the cabin the sub sound will get in there.  Believe it.  The sound pressure will fill the space, and with an opening it all becomes one space.

You've got a good handle so far on calculating air space.  You seem to have ability, so I suggest you take the step to using a box-building program like WinISD to help you calculate ports.  Read my sticky above and download the free program.  Take a couple of days making sure you get your sub parameters inputted correctly and start understanding what the program is telling you.  Slot ports are easily chosen over round in that program.  You can probably do it faster and have better results than asking around on the forums and using whatever Mr. Anybody tells you.