Fi SSA15, enclosure opinions and install questions

[scameron 0]

the sub should be here within the week. it will be going in a 2002 cavalier. i have limits on the box, so i have come up with 36w x 17h x 13d with 2 3"ID ports tuning to 35hz. i read some where i could tune the box a little higher due to the fact i listen to a wide range of music. any truth?? sub will fire into the cab area. i have also read some where about sealing off the trunk. so, i would seal off the enclosure from the rest of the trunk and channel all the sound into the cab area?? any specifications on space needed in front of the woofer or ports??