In the first case, the cigarette lighter can only be used to charge the mobile phone or tablet computer, but not to play.
In the second case, the USB interface inherent in the vehicle-mounted playback device can generally play in this case.
In the third case, the car has a playback device, and then its own USB interface may not be able to play.
Finally, the songs in the USB flash drive must be saved in a format that can be recognized by the on-board system.