OK, so it seems that if my iPhone 6s is in carplay mode, and the screen saver/timeout kicks in, that I am unable to launch/play iHeart Radio.
You push the icon on the Pioneer 4000 NEX (latest 1.11 firmware) for iHeart radio and it goes to the black screen that says iHeart Radio and nothing happens. wait several minutes. Nothing
Now, observe that my iPhone screen is black. So i click the button to wake it up and voila, iHeart Radio starts finally on the Pioneer unit.
Is this working as designed?
I thought that while your phone was in Carplay mode, it wasn't locked?