Haven't asked for box plans in a while on this forum so i don't know who to go to. It's for a 12'' Q in an rsx (hatchback). I'm thinking sub up, port back. ~2.2^3 tuned to 30hz. The dimensions are; 39 inches wide, 15 inches high, 26 inches deep.
"Ported box we recommend using 1.8-2.5 cubic feet @ 28-33Hz (I personally think that a 32hz tuning is optimal, and has the most output and is still the most musical daily driving). Use 12-16 square inches of vent area per cubic foot of volume."
-From the Fi forum