I have the same problem on my 00 323ci. I took the car down to BMW of SF and they simply related the problem to the brake linings and refused to service it. They claimed that it was a wear item... Shortly after I posted my experience with BMW SF, I was contacted by BMW NA and they advised me to take the car down to another dealer... which I did. At Claridge BMW, I was lucky enough to duplicate the problem and the service dept. agreed to take a good look at it... Several hours later, I got the car back and they said they've cleaned the pads and it shouldn't sqeak anymore... But guess what, the squeaking came right back the next day and it seems it's getting louder and louder... I've totally given up on this... (along with problems on the clutch, dash, and rear speakers)