Same problem with my Black Sapphire X5 50i...that I SPECIAL ORDERED. They took it back to the detail guys in the dealership, had it washed again, and then polished the affected area. All while I stood and watched. Swirls came out for the most part. I made the GM acknowledge the issue before i signed the lease agreement. Ultimately they disappeared.
BMWs are not known for their paint quality...especially black.