While there's no official changelog for what's new, an updated version of Android Auto is now rolling out to all users in the form of 7.6.
What's new with Android for cars
Google fixes call issues on Pixel phones with Android Auto
Pixel 7 and 6 owners encounter annoying Android Auto connection issues
Android version history - Wikipedia
Android Auto 7.6 update is cruising on out to devices now
Google announces Android Auto updates at CES 2024
Google Rolls Out a New Android Auto Update, Third Release in a Week - autoevolution
New apps for Android Auto and cars with Google built-in
Google Releases Android Auto 9.7 Update, Everyone Can Download It Right Now - autoevolution
Google announces Android Auto updates at CES 2024
New features for Android Auto and cars with Google built-in