IllegalArgumentException

Your code is pretty much fine. The only problem is that right above your try/catch block, the drive()-method is called. Since this call is outside of the try, the exception is not caught. Remove it or move it into your try block. The drive(-20) call is not necesarry in the latter case.

firstly there is no need to have two drive methods , drive(2) and drive(-20) Secondly, there is no need to write this statement in try, System.out.println("This will never happen");

you may use the code bellow and give me a shout if it helps

public class Main {
    public static void main(String[] args) {
        GoKart kart = new GoKart("yellow");
        if (kart.isBatteryEmpty()) {
          System.out.println("The battery is empty");
        }

      try {
        kart.drive(2);
      } catch (IllegalArgumentException iae) {
       System.out.println("Alert");
           System.out.printf("There was an error: %s\n", iae.getMessage());
        }
    }
}

try {
        dispenser.load(400); 
      } catch (IllegalArgumentException iae) {
        System.out.println("Whoa there!");
        System.out.printf("The error was: %s%n", iae.getMessage());
      }

Above, is the code example to follow. Instead of dispenser.load(400), you are trying kart.drive(2)