As a new convert to GrapheneOS, I can testify that it has everything you need: Aurora for privacy (Google store proxy), the real Play store if you want, Android Auto, and a lot of privacy features enabled by default. It’s restricted to the Pixels though which is the only issue.
https://postmarketos.org/
https://calyxos.org/
(Pixel Only) https://grapheneos.org/
(Stripped down Android, Pixel Only) https://pixelbuilds.org/
As a new convert to GrapheneOS, I can testify that it has everything you need: Aurora for privacy (Google store proxy), the real Play store if you want, Android Auto, and a lot of privacy features enabled by default. It’s restricted to the Pixels though which is the only issue.