I have a 2001 E320 wagon. I was wondering if anyone has installed either the DICE or Denison Gateway 500 Interface? I would like to install an Ipod and satellite radio. Can the factory speakers be replaced with aftermarket speakers since the system is fiber optics? Also,i don't know which radio I have it is AM/FM cassette. Is it a command orAudio 10, 20,30,50? The Dice unit is 359.99, and the Denison unit is 499.00.