I just got my new 2004 330cic last week and I love it !!! Iwant to replace the HK subwoofer with a better one and put it in the same place as the original one. It appears it is an 8" subwoofer and it located in a plastic type housing between the rear seats in the pass through area. Has anyone done such a modification? Any suggestion and pics would be great. The JL stealth boxes do not fit in the convertible according to the JL salesman. Thanks.