I'm trying to take one parameter from the parent class of Car and add it to my array (carsParked), how can i do this?

Parent Class

public class Car
{
    protected String regNo;       //Car registration number
    protected String owner;       //Name of the owner
    protected String carColor;

    /** Creates a Car object
     * @param rNo - registration number
     * @param own - name of the owner
     **/
    public Car (String rNo, String own, String carColour)
    {
        regNo = rNo;
        owner = own;
        carColor = carColour;
    }

    /** @return The car registration number
     **/
    public String getRegNo()
    {
        return regNo;
    }

    /** @return A String representation of the car details
     **/
    public String getAsString()
    {
        return "Car: " + regNo  + "\nColor: " + carColor;

    }
    public String getColor()
    {
        return carColor;
    }
}

Child Class

public class Carpark extends Car
{
    private String location;        // Location of the Car Park  
    private int capacity;           // Capacity of the Car Park - how many cars it can hold 
    private int carsIn;             // Number of cars currently in the Car Park   
    private String[] carsParked;

    /** Constructor for Carparks
     * @param loc - the Location of the Carpark
     * @param cap - the Capacity of the Carpark
     */
    public Carpark (String locations, int room)
    {

        location = locations;
        capacity = room;
    }
    /** Records entry of a car into the car park */
    public void driveIn()
    {
         carsIn = carsIn + 1;



    }

    /** Records the departure of a car from the car park */
    public void driveOut()
    {
        carsIn = carsIn - 1;
    }

    /** Returns a String representation of information about the carpark */
    public String getAsString()
    {
        return location + "\nCapacity: " + capacity +
             "  Currently parked:  " + carsIn + 
             "\n*************************\n";
    }

}