Sony RM-X4S remote controller is a resistive controller that has 12 buttons.
You can use it for Car PC(or Boat PC) with CarPC JoyCon Exr(Ex).
Put 5.1k ohm between tip and ring, to use the album+/- buttons.(5.1k ohm is better than 56k ohm.)
Turn the adjustment dial to the end of counterclockwise.
Do Auto-Detect in JoyCon Explorer.