I understand your pain interms of taking the car back, but in hindsight, they are still willing to help and have even picked other issues(which shouldn't have been there in the first place). Even though they have damaged the panels, again they are willing to replace it. I would be happy with the fact that they are still willing and not telling me to bugger off or no issues exist like with the M135i thread.
Also i have never purchased a new car so cannot claim to know exactly what it feels like.