The 328 has a Harmon Kardon CD stereo system.
One or both of the small speakers in the drivers side door panel makes a noise.
Can i source the speaker from other than BMW dealer???
Is it possible to just purchase a replacement drivers side door speaker and from where??

try this forum . . they are always selling speakers and different stuff . . . lots of traffic

http://forums.bimmerforums.com/forum/forumdisplay.php?s=&daysprune=-1&f=169

Good Luck ! !