I seemed to be able to get it to work. With a Nexus 5. On the car radio, I deleted the phone, changed the pass key to 0000, turned Bluetooth off. then started again and when the Nexus 5 showed car audio as a device, I long pressed it and the pairing worked. To get music on the phone to play thru the radio, I had to choose the "media" button on the face of the radio.
