Thanks, that’s what I understood. That’s why there is always a lag with the position of the car with maps on CarPlay while there is none with the car built in navigation system which uses odometry in complement of satellite navigation.Everything on CarPlay runs on the phone. The CarPlay screen is a secondary screen generated by the phone and projected to the car’s screen. The processing and GPS are all on the phone.
This is why it doesn’t take a lot of work for a car builder to integrate CarPlay or Android Auto. The phones basically provide a video feed that the car can show on its screen. There are some touch events and audio events that are pushed back to the phone over the CarPlay APIs, but all of the processing happens on the phones. That is why a new CarPlay version can launch and the car doesn’t even need to know about it.
Even with a less refined look, I much prefer no lag.