It is time to seek out another dealer.
There is no reason the top should have an issue like that.
It would help us to help you to tell us the location of the noise sources.
I know Kat has some information regarding corrections to the front windshield area.
Totally serious about locating another dealer. Has the dealer acknowledged the noise? If so try another dealer and if that doesn't work raise the bar and request BMWNA get involved politely through your dealer.
Hope this helps and please tell us the noise location(s)...