Bushing on a 2000 Malibu

What happens if you do not get that repaired?

Which bushing are you talking about?

when you drive the car you hear a clunk in the right rear end of the car every now and then, my son seems to think it is a bushing

When a suspension bushing has beaten out, the component it used to hold will move. As a result the wheel alignment will wander unpredictably causing directional control problems. The car may have a tendency to dart to the either side unpredictably. It is best to get it repaired as soon as possible.