I'm going with this...
To be used with the camera kit. Just run the USB to the trunk and into the dac and toslink into my Helix p-dsp.
iPhone 6 Plus (iTunes library/iTunes radio/Waze, etc) to Airport Express via AirPlay. Toslink out of Airport Express to Helix P-Six DSP. PHD AF 1.C tweeters, PHD FB 4.1 midranges. Jehnert Door Cards and mid-bass'.