At present I connect to the usb of my car and the head unit is connected to my helix m5dspmk2 and I listen to everything to everything via android auto on my phone. I was wondering if anyone is aware of a way I can continue this setup but some how get the audio to the optical input of my dsp so it bypasses the head unit? I was thinking of getting a bluetooth receiver with optical output which obviosuly I could use without android auto in the loop but I cant find a way to get my phone to force audio over bluetooth when android auto is running over usb, (I have been experimenting bluetooth headphones)