I can here it now. Customer: My car has a really bad rattle in the door panel and behind the dash and in the head liner. Service Advisor: That's the sound system. BMW adds rattle sounds along with clunks and buzzing to give it a performance feel. Waste gate rattle...nope that sound is an option. Only 2K extra.
Currently own: 1965 Backdraft Cobra Replica, 2013 SVT Raptor, 2009 Scion XB and 2004 Malibu VLX