Thanks for the comments. I got an email from the dealer's workshop technical manager who said he's in contact with BMWNA and now has tests he has to perform. I can't say I have any idea what that really means, but I'll give him a day or two to play with the car. They gave me 2011 335 to tool around in, so I guess I'm happy for now. Depending on what I hear from the dealer next, I may place the call to BMWNA to make sure I'm on record with the issue.
Good luck with the rack replacement. Let us know how it works out.