Just saw this article and thought I would share (specifically interested in "CarPlay can automatically launch an app like Spotify every time you connect the iPhone to the vehicle, all without you tapping the app’s icon manually").
It might be nice to be able to pull up music AND Waze as soon as I plug in my phone, especially with the buggy-ness of carplay and my Honda infotainment system. Worth a shot!
Summary of how to do this from your phone: Shortcuts > Create Personal Automation > CarPlay > Connects > Add Action > Scripting > Open App > Choose > Spotify > Next > Done