@Timekeeper @JetForMe @chockenberry It’s more about the structure of CarPlay. It doesn’t necessarily provide the car access to anything. The UI is rendered as a video on the phone which the car simply plays. The car could still record what you say and what Siri says, then run its own speech-to-text, but it can’t just dump your whole address book.
This issue is because so many car manufacturers write their own UIs to present phone stuff in a standardized form. They use Bluetooth MAP, PBAP, and other things to dump categories of structured data which they store. They then display the data from their local storage in the car manufacturer’s UI. It’s how they integrate with non-smartphones, for example.