Hi everyone,
I finally managed to fix my pixel to car Bluetooth issues. Bluetooth would always connect but sometimes the car couldn't see it as an "Audio device" and no sound would play. It's been like this since i recieved the phone in October so thought it was the cars system not being compatible or something. Then I found if i rebooted my Pixel to safe mode, it synced with the car straight away, and the car interface displayed all the song, album and artist info. So, what was causing it, after much uninstalling of apps, I found one called "Headset Droid", i'm not even sure what it does, all i know is that the moment i uninstalled it, the car audio kicked into life and everything worked like a dream!! Am so relived to finally get it working. I'm using the standard size Pixel, on 7.1 connecting only via Bluetooth to an Audi A1. A lot of the posts here lead me in the right direction so thanks everyone! Hopefully this might help somebody else out there