/**
   Represents a car.
*/
public class Car extends Vehicle
{
   public Car(double purchasePrice)
   {
      super(purchasePrice);
   }

   @Override
   public double getValue()
   {
      double adjustedValue = super.getValue() - 0.25d * getMileage();
      return (adjustedValue > 0) ? adjustedValue : 0;
   }
}