Swing/AWT/SWT :: Iterating Through Objects To Draw On Panel?

I currently have the code set up to iterate through objects and keep track of them but how do I do the same and draw the objects on the panel window? I'm confused on what to do and how to start it.

Here's the code I have so far, the 'Car' which I want to draw extends to another class which extends to GameObject. I currently have a 'draw()' method under the 'Car' class but nothing in the 'draw()' method yet. From what I understand i'm suppose to have a 'draw()' method under 'GameObjects' class also?

public class MapView extends JPanel implements IObserver, ActionListener{
JPanel myPanel;
private Timer timer = new Timer(5, this);
int x = 0;
int moveX = 2;
public MapView(){
super.setBorder(BorderFactory.createTitledBorder("Map:"));

[code]....

Mostly I don't understand how to go through the iterator again to paint the objects. Wouldn't I need to put another iterator under 'paintComponent()' or can it be done under 'update()' ?

how to get some shapes from the GameObjects onto my panel.