My dealer provided me with a copy of this BMW Service Bulletin. Instead of scanning, I'll just type the text:

SERVICE MEASURE
Phone, Navigation Systems B84 226 04 August 30, 2004

Subject:
CPT9000 (V60s) Telephone Landside Echo in Hands-free

Complaint:
An echo niose can be heard from the landside party while in a hands-free call.

Cause:
DSP sensitivity of TCE (Telematics Control Unit)

Measure:
Currently this complaint is under investigation. This measure will be updated as soon as a resolution is available. In the interim inform the customer of the following recommendations in order to reduce the echo.
- While in a hands-free call make sure all windows and sunroof are completely closed.
- Turn the hands-free volume heard in the vehicle down.
- Direct the heating and air conditioning center vents down away from the microphone.


Hope this helps people out - sounds like a fix is on the way.

 

I'm sure that will help out a lot of owners.

 

I also had problems with my BMW BT kit and Nokia. Not an echo, but very muffled sound coming from my side of the connection.

I had to eat Strepsils every day 'cause of the shouting into my carkit......

The dealer changed the microphone, it became a little better.

Now, I tuned down the volume on the phone. Apparantly the phone memorizes a volume on the phone (the Nokia) which you can adjust while you are on the phone.

Tuning this down increased the quality of the sound coming from my side of the connection tremendously! I've now tested it on all sorts of roads with several speeds. It's great.

Thanks to your thread on roadfly, Wolverine, someone suggested this.....

Bye.