Deja vu! I took my previous BMW (a 2004 gray 3 series convertible) to BMW Seattle for warranty service about a year ago. When I got it back, it had a white scrape all down the passenger side, which looked suspiciously like the white posts they have holding up their parking area awning. (And that has a lot of scrapes along the posts, right about where a car door would reach. Lot boys being in too much of a hurry? Hmm...) They cleverly tried to hide the damage by washing the car, but delivering it while it was still wet. On a gray, rainy Seattle day, it was easy to overlook.
When I got home I discovered the damage, I called them, and all hell broke loose on the phone. They denied doing it, of course, and I threatened to call my attorney, also of course. In the end, they fixed it at their expense while I drove one of their brand new 3 series coupes for a week.
Dave