I just picked up my MINI CVT last week and everything is great so far with the exception of an interior buzzing noise while driving. I could hear the noise on my left ear and after doing some research, I discovered that it was coming from the interior door panel on the bottom lower corner facing the doorjamb. Basically, what is happening is that the edge of the door panel is vibrating against the metal on the actual door. Because door panels are attached to the door by snap clips, it does not provide a solid attachment like say if it were bolted on. There are 3 screws near the interior door handles, but those do not provide the solid seal that is needed for the vibration to stop. A good way to determine what area of the door panel is not making a solid seam is to open the door and lightly tap near the edge of the panel with the side of your fist. By taping, you will hear the same exact noise that you hear while driving. Once you determine the culprit area, you will have to get a thin rubber band that is 1/4" wide and cut it. Now lay the rubber band flat on the metal part of the door near the edge of the door panel. Then use a small screw driver (I used the screw driver from my Leatherman Micra tool and it worked quite nicely) to slowing tuck the rubber band in between the door panel and the metal door. Work your way down until the length of the rubber band is wedged between the door and the panel. Be sure not to tuck the rubber band completely under the door panel otherwise you will have defeated the purpose. Leave about 1/16" or 1/32" of the rubber band exposed along the edge of the door panel. It is hardly noticeable.
What the rubber band does, is acts like a shock absorber to prevent any further vibration between the door panel and the metal base of the door. I was thinking about taking it to the dealer, but frankly I don't think they could have done a good enough job as myself, since I know exactly where the noise was coming from.
I know this does not seem like a professional fix that BMW customers might be used to, but the only other way to fix this problem is for BMW manufacturing to add a permanent rubber film on the interior door panels during production. The dealer simply cannot fix this and therefore you must do it yourself. The total time I spent on this fix was about 8 minutes and now my MINI is super quiet.
Cheers,
Al,