Please be patient, I'm more of a motor tuner than audiophile but I usually get around to installing stereo stuff after performance stuff. I have the 2001 330i with HK system. I have been researching the forum for recommendations about audio upgrades. I take it that the rear speakers are weak and need to be replaced. I want to keep the head unit but can/will replace any other components starting with speakers. Can you guys recommend the first component I should replace ie, rear speakers, and what do you recommend for <$500 for this component. Thanks!!