Choosing Waze on the Android Auto phone interface is handled just like it is in the car. Double-tapping the navigation icon in the bottom bar now brings up a list of available navigation apps where you can select Waze if it's installed and set up on your device. The advantage of using Waze inside Android Auto, rather than just opening the app, is that the new method also grants fast access to all of the audio, media and messaging apps that are also compatible with Google's car mode.
For now, Google Maps and Waze -- which is owned by Google -- are the only Android Auto navigation choices available. Recently,that it will be supporting third-party navigation apps, including Waze, in its updated Apple CarPlay software.