The fix is a new thrust bearing in the clutch. big job clutch out! BMW fitters only do basic fix they cant be botherd to lube the thrust bearing it takes just a few minits to do or replacement is only £10 but they don't have to listen to the rattels that we do!!
hope this helps or you can get on to BMW for telling lies to you. if they had fitted two new clutchs way have you still got probs with rattels. go on get the boot in!!