Hi
I've started using my S2 again after 1½ years, and one time on each suddenly there comes knocking sound (as if something hits the body), and only once. First time it came it was after ½ an hour, and I thought it was a stick being slung up at the body. I think it's different to an exhaust "pop", and my only idea now is an worn UV-joint, but that does not make sense either.
Cheers