AFAIU things have changed with the newish update to bluetooth in AppSupport.
Previously we only had native bluetooth support, so you could pair your device and have audio routed through bluetooth to your car, but obviously your android apps wouldn’t work.
There has been some progress with native support for Tesla, as discussed here.
When they brought bluetooth to AppSupport, this allowed Android apps to work, with the exception of audio which again AFAIU, is only supported natively, and maybe that’s the issue you’re having.
Bluetooth can be quite fiddly at the best of times, but perhaps you need to make all devices forget each other, and stop AppSupport completely to be sure. Then pair just the car media centre with your phone. Then once you get it working, try to play with getting the Android side going