If you have a CRADLE that your iPhone snaps into then YOU MUST have 6FL (iPod/ iPhone integration) AND 6NF (Smartphone Integration) AND the Premium Package.
With these options I DO NOT BELIEVE that yoiu can use the Y cable that comes with the 6FL. You need to use the CRADLE that your phone snaps into. So NO cable will help.
To use you iPhone in the car the Bluetooth DOES NOT REQUIRE 6NF or 6FL only the Premium Package. If you snap the phone into the cradle then the telephone itself (calls, transfer of phonebook etc.) will use the Bluetooth connection AS WELL the phone WILL charge AND the phone will use the EXTERNAL ANTENNA.
With the iPhone snapped into the CRADLE the audio from the iPod functions of the iPhone will use the hardwire connection afforded by the 6FL connetcted to the Smartphone connections and should appear on your display and play through your radio.
If you need more help e-mail me provatelt and I will assist further.
M3 GTR - 1/5 scale - 4.2 HP w/ Collari hydraulic brakes - would you believe ~80 MPH on straightaway !!