CarPlay and Android Auto actually work well, and you can use the apps that you already have on your phone. The screens are generally more convenient and restrict view less than a phone holder stuck to the window. But without those, I agree that I’d rather have no screen than one with crappy media controls and the car’s own navigation.
That’s it! If you don’t specify a host path, i.e. the path before the colon, Docker will create an volume which saves any changes you make to that path in the container, but won’t mount any existing path from the host to the container.