I have the Schuberth C3 with the BMW bluetooth unit and an iPhone 4S. To answer the questions, if you use a 3 pole 3.5mm connector/cable between the iPhone and the Aux input in the right cubby, you can both listen to music via the hard connection and make/accept calls via bluetooth (helmet speakers & microphone). When the call ends, the music returns.
I want to be able to hear and use the NavIV, so pairing the iPhone to the helmet won't work as desired (helmet unit doesn't support 2 A2DP connections at once and no way to easily cycle between them).
Here is my setup. I got tired of using a ziplock bag over the iPhone when it rained, so I modified a Think Biologic
bike mount for the iPhone. The thing I like about it is it's essentially waterproof (tested in a few deluges), even with the 3.5mm cable plugged in. The mount did require some modification, which you can see here
(I would post pictures, but the retarded way this forum requires text to be entered for a links, makes posting thumbnails with links to the larger images a pain in the @$$ - Rant Off).
The 3.5mm 3 pole cable is routed under the seat to a MixIt2
, which allows for me to add other sound inputs like a radar detector, etc. For $159 it's a lot cheaper than an autocom.
I then route a 3.5mm 3 pole cable from under the seat to the right cubby and the Aux connector. Works like a charm. With the bike audio set to AUX, I get any audio out of the iPhone (music and Navigon GPS routing), along with radar beeps set to override the iPhone output, along with NavIV audio overriding the AUX.
For long trips where I use the Ultimate Ears in-ear monitors, I can plug those into the MixIt2, forgoing the AUX input and still have the bluetooth helmet connection for the NavIV and phone calls.
So far, it's been pretty reliable and I'm happy with the results.