Adding a subwoofer
Looking for some information from someone that has added an external/additional subwoofer to a Harmon Kardon-equipped C63.
Before sump of you jump in with the "The engine should be the only music you need" type comments, I more than occasionally have to sit in traffic so a solid stereo is very important to me!
What I need to know, from people that have done this, is where they took the input signal from or what hardware is required in order to generate a signal.
Many thanks in advance,
Si



