Pixel 8 Pro, Pixel A-Series Earbuds - How do I listen to my buds while using Android Auto?

I have a Pixel 8 Pro and the Pixel A-Series earbuds. Is there any way to have a phone plugged into a vehicle and running Android Auto and still only listen to audio via an earbud? I'm hoping there's a way within the OS to route auto to the earbud without the sound coming over the car speakers.

Same goes for when you enter a vehicle and the phone automatically connects to the car's bluetooth. Can you route the audio signal to just the earbud somehow?