I got the cord from the apple store and it works great from the auxiliary port, but it is not controlled from stereo. Is there something that can help me do that? I do not have the navigation package.
Mine also comes with the aux-out only. To connect to the audio Head Unit so that you can select/browse song titles, you will need a usb connection in your Z4. I know you can installed that with an option to replace the aux-out connector in your center console with a combo (aux-out and USB port) but that's not a cheap solution. It will require rewiring to your audio Head unit.
I supposed the current setup with the aux-out is to plug your cable to the headset connection on your ipod. From sound quality perspective, that is the worst as I understand that the ipod will do the DAC function and treat the connection like a headphone output. The other more elegant approach is to connect via 30pin connector (docking port). This, i understand will allow the ipod to stream raw digital data to your Head unit to do the processing (DAC). If you have a sound processor, you can also link your HU to your SP and let your SP do the DAC conversion before pumping it to yr amp and speakers.
Sorry for the long reply. Just some options you can explore.