First, I don’t think anyone calls the adventure experience occy, stretchy or twangy jumping, so I’ll stick with “bungy.” I now think I get the point, the loose end was clicking against the rear window, making you think it was something much worse, and it has nothing to do with your tires going bad, other than making you discover it. Can’t help you with the tires, but I could send you a new bungy.
Richard L.