Is siri not being required a toyota thing? My only experience with CarPlay was in two different Volkswagens a couple years ago and Siri had to be enabled for the head unit to connect to the device, period.
You are correct. I was wrong about this.
While you don't need to use Siri to enter interact with Google Maps or Waze while using Car Play, Siri is used to play messages. I don't know what would happen if you tried to disable Siri.
When I used CarPlay in a rental car, I set my map destination with my phone before I started moving (just as I do normally in my LC which doesn't have CarPlay). I then used the on-screen map and controls as needed.