If you are using the Y cable, you likely don't have the combox. Combox started with Sept 2010 production but BMW was selling model year '11 here in the US before that so you could have a MY '11 without the combox. My Sept '10 build car has the combox and I use the standard white Apple cable to connect my iPod, no Y cable needed.
You can do the upgrade so search for some of the vendors offering it...
2011 Space Grey E90 M3, DCT, Comp. Pkg.
1997 Z3 2.8, Artic Silver, Tanin Red interior, MT
1974 2002tii, Inka, MT