3. "It reads it to you and then asks you if you want to reply" In response to In response to 2 Tue Jan-15-19 05:44 PM by sectachrome86
If its a new message coming in it shows up briefly as a notification and you can tap it to read it. Otherwise you just open Messages and select from there.
Also CarPlay has kind of a "dock" with shortcuts to your 3 most recent apps. Messages is usually one of them, so I don't have to go home first to open it.