I had a clunk in the rear on my 78 Trans Am. Took it to the dealer. Took the service manager for a ride, he heard it. Made an appointment to bring it in.Lately when turning in either direction I hear a clunk like noise coming from the rear. I did check the trunk nothing moving around. If I take off from a stop and turn slowly I will not hear it. Just when I turn with a little speed. Any thoughts???