Finally I was able to improve the audio quality for the person on the other end. My dealer attempted to install the RAZR cradle which would have used the shark fin antenna. On my build of the car this did not work. The byproduct of this attempt was that I got the latest and greatest version of the software which improved the audio quality. My son has an 06 330 and his Bluetooth audio quality is fine. My service advisor tells me that the Bluetooth audio quality issue has been addressed on a rolling basis with the newer 5 series cars.