A new version of Android Auto has been released, and the GrapheneOS mirror on their appstore has updated. *OR* You are connecting your GrapheneOS device to Android Auto for the first time.
a. In system settings, navigate to Settings > Apps > Sandboxed Google Play > Android Auto.
b. Allow all permissions.
a. In system settings, navigate to Settings > Apps > Sandboxed Google Play > Android Auto Settings.
b. Scroll to the bottom to see the "About" section.
c. Quickly click on "Version and permission info" 10 times to enter developer mode.
d. Click the three dots in the upper right-hand corner.
e. Select "Developer settings".
a. Within developer settings, scroll down to "Unknown sources" and select the box to check it.
a. Restart your device.
You may need to reconnect your device to your car via GrapheneOS' bluetooth menu after the system restarts.