Hi Bankerjq,
Sorry for the delay in this reply.
Last time I discussed with Cardo systems via email, with my Cardo reseller shop, with a Cardo representative and with BMW reseller, beginning of this year (Feb 2012) , there were no solution from Cardo at all.
Nevertheless I cannot swear that the G4 does not work because I did not tested it personally (I believe only what I test by myself ...on paper everything works fine!)
So if you have the chance to test G4 thanks for posting the result here.
In the meantime I bought the "super expensive" BMW helmets with the "even more expensive" BMW intercom...in my case x2 because the K16 bike is designed for 2, and my girlfriend is, as well, my banker !
The BMW system works but not as I expected... here my experience: -
Driver helmet: GPS messaged reception: OK
My cell phone: talk and reception OK
Intercom with passenger Helmet OK but....( see limitations below)
Radio reception OK but... (See big limitations below)
-
Passenger helmet: Passenger Cell phone OK
Intercom with Driver Helmet OK but.... ( see limitations below)
Radio reception OK but... (See big limitations below)
LIMITATIONS with BMW INTERCOM SYSTEM- The Intercom is a mode: this means you have to manually switch from Radio to Intercom (and back) . I would have expected an automatic switch when one of the passengers starts to talk. This is not the case and the DRIVER has to switch the mode to intercom to start the discussion (your girlfriend in the back can be a bit frustrated is she wants to speak and you are listening music ...but may be this feature can arrange some of us ?

... from my point of view it is not optimal for such a high value system.
- The Radio: here it is even worst: The radio can only be listened by 1 helmet at a time: This is completely crazy!!! Depending on the first helmet turned on, either the passenger or driver's helmet “gets the right” to listen music! Apparently the Bluetooth system does not have enough channels to send the music/radio stream on both helmets? (so the explanations of my BMW reseller!)
What is the reason not install an additional emitter? Here as well if you drive most of the time alone it could be acceptable…
But as said, I bought this high end bike to drive with my girlfriend.
Not be able to share good music while driving in the rising sun with the glittering stream along the road , kills any potential of romantic mood

!
Regards,
Marcel , the romantic Puppy