Dan-cer I believe the Google Play suite works together so closely that it is necessary to install all of it for any of it to work, and thus necessary to install all of it for Android Auto to work. That said, I am not an Android Auto user (yet?).
Dan-cer All the apps I need are installed. So I have now uninstalled the Google services with clear conscience.
That's not really how it works. Many apps depend on the Google Play ecosystem to run. Some apps can run with or without it, but they configure themselves the first time they run based on whether Play is present or absent. If you want to use some apps that require Play, and want to use some apps without Play, one approach would be installing Play in one user profile and installing the apps that want Play also in that profile.