Hi guys, I'm new to the site and also new to the BMW community as I have just purchased a '00 BMW 328i sedan. My car came equipped with the Harmon Kardon speaker system but upon purchasing the car I noticed the 2 rear shelf subs are blown as are the 2 lower front door speakers. I work at Best Buy and asked my car audio installer about my options as far as replacement goes. From what I've read the Harmon Kardon system isn't all that great anyway so I'd rather not pay a premium for some oem replacement speakers when I get great prices on audio with my discount. I found some Alpine SPS-500 speakers at my job which fit the 5 1/4" size that I need but the install guy said that the way the system is set up I am only gonna be getting lows from the speakers which isn't what I want since the mids and highs provided by the other speakers arn't all that. So my question is the following...Is there any truth to what my car install guy said? and if so how do I bypass or correct the problem so that I can get the sound I want? Also, he mentioned that I could only get lows out of the rear shelf speakers also so even if I attempted to replace them with some aftermarker speakers I'd have the same problem. Would an aftermarket radio correct the problem. Thanks in advanced for your help guys and please excuse my newbiness.