Well I got the port crap figured out. Now I am moving further into the build. Go to post # 13 to see progress. The rest is trying to figure out port area.
I plan on using 3 4" aero ports that I have in hand, both ends flared, precision ports, and the box is roughly 5 cubes after dd and PD, The subs are 4 RE SE 10"s powered by a JBL BPX2200.1 so power is not an issue. these are going under the rear seat and I plan on side firing the port to the drivers side and the subs are front firing. Seat is raised 4" to get this to fit and the bottom is fiberglass. Ill double the front baf and recess the subs.
I have only used slots and have gone by the 10-15 ci per cf of airspace. Aeros are dif and I'm not a pro on thse suckers. Ill be tuned to around 33 so the ports will be 16-17 long depending on what my final airspace.