Here is my system.
Head Unit: Clarion ARX7470
CD Changer: Clarion CDC- 635
Equalizer/Crossover: Clarion EQH5100
Inline Amplifier: AudioControl Matrix
Highs Amplifier: Crossfire CFA-402 (100 WRMS X 2 @ 4 ohm)
Lows Amplifier: Crossfire CFA-1000D (1000 WRMS X 1 @ 1 ohm)
Components: a/d/s/ 235is
Subwoofers: Rockford Fosgate RFP-1212 (2)
Security: Clifford Intelliguard 7000
The main intention of the installation was SQ rather than SPL (but obviously RF subs don't help ), also a very nice and clean trunk where the spare tire were still available.
The Sub enclosure was made with 3/4" MDF and then, covered with a 2mm-fiberglas layer and painted as the same color of the car. The back of the enclosure is a 3/4" Plexiglass and purple neon makes the whole thing look nice. All the covers were made with MDF and covered with light gray vinyl from Select Products.
This is the system diagram. Brown color means data lines, green full range, red high pass and blue low pass signal.
During the installation process, the CFA-402 driving the a/d/s/ components is shown in this picture. Also, the components crossover are seeing and they were covered with plexyglass, the a/d/s/ logo was painted as well.
Again during the installation process. The CFA-1000D is on this side of the trunk.