Factory Auto Sound / FAS Group - Custom subwoofer enclosure for a BMW Z3 Roadster. 8" Hertz Energy woofer. 6.5" Hertz Energy components and a 5 Channel Hertz amplifier as the power
BMW Z3 custom subwoofer box. Build overview - YouTube
Simply Speakers - BMW Z3 Speaker Subwoofer Repair
Wicked C.A.S. > BMW > BMW Z3 M COUPE 99-2002 10" Magic Box SUB BOX SUBWOOFER ENCLOSURE