I have a 07 328xi, I have a nav which means I have idrive. I do not have logic 7, does that mean I have a hifi system or...? From what I see is 6 speakers, 2 under the seat, two 4" speakers in the front and rear. I plan on upgrading all the speakers, even the ones under the seat. Besides the amps and speakers, what else do I need to buy or do. I have read most of the other topics , but almost all the upgrades are being done on a 335 which comes with logic 7.
