How do I set up Roon ARC to play through the Tesla audio system.
Not quite sure what you mean by set up Arc to play through the Tesla.
If you have already set Roon Arc up with your Roon Core all you would do is connect to the Tesla via Bluetooth or whatever wired option it has for your phone( no idea, never touched a Tesla).
Additionally, if you wish for a deepeer integration, don’t hesitate to add your vote to the following feature suggestion:
Unfortunately Teslas don’t support wired connections. Just connect your Apple or Android phone via bluetooth to the Tesla, make sure bluetooth is selected as the audio source.