Here is my experience, its all about the Dealer!! And right or wrong, if you havent spent any money with a Dealer is he going to go out of his way to help you?
In theory if all Genuine parts and BMW schedules have been followed then you have a right to a warranty claim, but will you have problems? Yes you might.
Personally I think a Good relationship with a "Good" BMW dealer is worth its weight in gold, but they are hard to find, your call.