I have a 2005 645ci that has had no problems other than this one: when driving on anything other than a flat road, there is a squeek or rattle in the dashboard. It seems to only happen when the car is torqued or flexing; that is whenever there is a slight bump or roughness in the road. I reproduced the noice for the dealer and they replaced the windshield because they thought it was loose, which of course did no good. I recently took it in for a small repair to a non-dealer and they believe it is definitely something in the center of the dash that is loose, and that the dash will have to be removed to find it.

The only other thing I can add is that it generally does not happen when the car is cold, only after I have been driving for a few miles and it takes much longer to show up in cold weather than in hot weather.

It almost sounds like something is rubbing against the windshield (that is, it is a squeeky rattly), but we now think it is really a rattle inside the dash. It makes no difference if the tope is open or closed.

Any thoughts would be appreciated.