in the following post:
http://www.e90post.com/forums/showth...fairing&page=6
this user tried the Thule Fairing on the oem bars, and he said it fit a bit snug. There are some pics to look at on the post. Apparently, Thule is now providing 2 different attachments with the Fairing. They used to only provide square looking threaded attachments, now they have oval ones as well. In the pics, this guys is using the oval ones. Im pretty sure when ordering the Thule Fairing, you may need to request the oval ones.
At least we know they make them. Still they are not meant for the BMW OEM bars, its a tight fit, but this guys says it hasn't given him any issues.