I own a 1999 ML320 with 120K miles (still a baby). Recently I heard a "rummbling noise" and knew immediately that I had an exhaust leak. Took vehicle to the shop and was told by the owner that he had never seen such a thing.....2 of the 4 exhaust pipes literally disconnected at the original manufacturers welding points. Has anyone ever heard of this?? This vehicle has been kept in perfect condition, never abused in any manner!