Sorry I didn't take many pictures of the process, but here's the jist!
The box 4.8 cubes tuned to 27.8 hz via 6 inch aero. 5 ply birch double baffled front, fiberglassed inside.

The subs: 2 skar VVX12 (one has a somewhat bad glue job from factory :\ )

Box in the car:

Amp Hifonics HFi 2500d @ 1 ohm:

Box and subs in:

The car: 2001 bmw 325i (few cosmetic mods)

HD Videos will come soon!! (this week, I'll update post with vid)