Update from yesterday. Was at the dealer and also talked to the mechanics. They said that the pulley can be worn out in the rubber and cause vibrations, and the enginge support on right side slowly looses the vacuum will cause this noise. I almost belived it but when they said that the replacement cost for this two parts was approx EUR700 I wanted to convince myselves a bit more.

Took the car to a garage and had the belt and balance wheel removed. My thought was that if the hub looks perfect, a new balance wheel might help.
Here is the centerbolt and hub when the car is on idle: https://www.youtube.com/watch?v=y3-yR2CP8kk
The hub is also wobbling, probably approx 1.0 mm. I can not in any way belive that BMW engines has tolerances on the outgoing axis of the motor like this. There will be heavy vibrations when the balance wheel is rotated off center like this at 700 - 7000 RPM.
I've spent 15 years of my life as and engineer at Saab Automobile until the bankrupcy and I can say by experience that the rubber in the balance wheel will loose it's mechanical properties shortly.

The seal around the hub was not changed which also suprices me when you do a repair like this at a main dealer. It looks like some kids has done the job. They are also MINI-cerified with fancy glass walls so I would expect more, but an independent garage is problably better.