So went to my local BMW dealer to have my engine oil + filter changed today. I specifically asked for 5W30 Castrol Edge and stated that I would like to keep the empty bottles after the job was finished.
We added a few more service items to the joblist, and then they started working on the car. As I later went to have a look inside the workshop, I found that they had just emptied the engine for its old oil, changed the filter and were moving a barrel of Castrol oil towards my car.
As I looked closer, I found that it was a barrel of 0W40 oil. I complained, and they instead found 7 x 1L bottles of the right oil...
http://v.youku.com/v_show/id_XNTA4ODk0MTQw.html
I don't know if something like this could ever happen outside of China, but now you are warned...