REAR SHOCK UPPER MOUNT ATTACKED BY CORROSION, VEHICLE ONLY 4.5 YEARS OLD AND 60,500 MILES. UN-PAINTED POT METAL LIKE MATERIAL BROKE UP INTO MULTIPLE PIECES WITHOUT WARNING. ONE MINUTE VEHICLE DROVE FINE, HIT A TYPICAL PAVEMENT EXPANSION JOINT CAUSING A LIGHT CLUNK TO DEVELOP. WITHIN TWO MILES I PULLED OVER TO INSPECT BECAUSE THE HAMMERING IN THE SUSPENSION GOT SO BAD. FOUND THE REAR SHOCK ABSORBER WAS NO LONGER RETAINED AT THE UPPER END. VEHICLE COULD STILL BE DRIVEN HOME GENTLY BUT THERE WAS NOTHING RETAINING THE COIL SPRING TO THE BODY OTHER THAN GRAVITY. BOTH UPPER MOUNTS WERE REPLACED WITH PAINTED REPLACEMENT PARTS FROM THE DEALER. THE LEFT REAR MOUNT HAD NOT FAILED YET, BUT CORROSION WAS RAPIDLY TURNING IT INTO POWDER FROM THE TOP DOWN. *TR