The product does not power off automatically after the vehicle is turned off. How can I resolve this?

This is related to the power supply policy of the vehicle's USB port. The power supply logic differs between vehicles: some vehicles cut off the power immediately after shutdown, some do not turn off the USB port power supply right after shutdown, and some keep supplying power continuously. If this bothers you, you need to manually unplug the device after getting out of the car, or simply turn off the phone's Bluetooth connection.