Sorry about that. I misread your post.
You spent 4 months huh? You are pretty patient.
Did you really think that you might have a case?
BMW just does NOT give a crap about what happened to their cars after the warranty period is over.
They are so fool of themselves that they do not need you, me or few others. There are enough people buying their products whether those products have issues or not. So this is their logic.