How to stop CarPlay from auto-connecting to your iPhone
According to Engadget, iPhone users can keep Apple CarPlay from auto-connecting by disabling it in iOS settings or using Screen Time restrictions.
Engadget explains that CarPlay normally remembers a paired iPhone and reconnects automatically when the driver starts the car. For anyone who doesn't want CarPlay to launch on every trip, or who wants to conserve iPhone battery, the feature can be temporarily disabled without removing the pairing. In the iPhone Settings app, users can go to General, tap CarPlay, select the car in the list, and turn off the CarPlay toggle. To re-enable CarPlay, repeat the steps and switch the toggle back on.
For older cars that don't support that toggle, Engadget says users may need to tap "Forget This Car" in the CarPlay menu. That action disables CarPlay for that specific car, but does not affect other vehicles paired with the same iPhone.
A more complete block is available through Screen Time. According to Engadget, iPhone owners can open Settings, go to Screen Time, then Content & Privacy Restrictions, and find Allowed Apps & Features. Disabling CarPlay there turns off the feature entirely.
As for whether there is any benefit to turning off CarPlay, Engadget notes that CarPlay puts navigation and streaming apps on the car screen and generally offers little reason to disable it. Still, some users may want to drive with fewer distractions, limit the number of notifications on the dashboard, or save battery during long days without a charger. Engadget also points out that using wireless CarPlay can interfere with AirDrop, so turning it off may make it easier to share photos with friends or family while in the car.