Originally Posted by PrazVT
If you are able to listen to music, browse your playlists with a standard apple usb / dock cable, that is the preferable option so stick with that. The usb/analog cable option is the default feature for folks who didn't get nav or the enhanced usb/bluetooth option.
...which doesn't automatically make it the better option. Just saying. I know for a fact that the line-out of iPhone/iPod dock connectors is very good (straight signal, no EQ, good DAC). This signal would be fed into the BMW via the Y-cable without further analog/digital conversion. So I would believe that way it has the least "signal loss" and tampering.
The other way, feeding the BMW through USB alone, would mean that compressed sound decoding would happen on the car's side, not the iPod. It would also include A/D conversion in the car. I am not sure if they use good components for that.
Not trying to argue here. Just wondering.