I think, jentr, that is the rear aerodynamic piece to the M sport package. I am a nooby here and this is my first BMW. I bought a CPO 2011 jet black Z4 3.5i with black interior about three months ago. It has the premium package and navigation. I am really enjoying it and the information that I am getting on this site. After seeing some of these great shots, it looks like new wheels may be in my future.
