BMW E46 Convertible Custom built Armrest Bass Box with 8" Car ALPINE Subwoofer | eBay
BMW E46 Convertible Hertz ESF20.5 8” Car Subwoofer installation in custom box and Hertz HCP2 Amplifier to drive the subwoofer. Really great sounding bass... | By In Car Music | Facebook
Ideas of factory looking subwoofer for E46 M3 Convertible - NA M3 Forums