I think you are seeing the Auto Start/Stop button. Is the one you are seeing an "A" with a circular arrow going around it? If so, that's it. Became standard starting with Sept '10 production. Or as it is called around here, 2011.5! I have it on my Sept. '10 build 2011 car...
Edit: the-moss beat me to it!
2011 Space Grey E90 M3, DCT, Comp. Pkg.
1997 Z3 2.8, Artic Silver, Tanin Red interior, MT
1974 2002tii, Inka, 5 sp manual