Hey, so with an update this week, Google Voice now works with Android Auto’s notification system. What I mean by that is Google Voice notifications can now be played over Android Auto as they roll in. It’s shocking to think this hasn’t been there all along, but then again we’re talking about a Google product.
An update hit Google Voice (2019.14.240805279) within the past two days that likely enabled this functionality. Be sure to update if you haven’t, because you’ll now be able to listen to Google Voice notifications and reply back, just as you can with Hangouts and other messaging apps. You should be able to initiate a Google Voice message too, though I haven’t tested that yet.
Google Play Link