2002 BMW M3 Suspensionrear Problems

AFTER 2.5 YEARS OF OWNERSHIP OF VEHICLE A SLIGHT "CLUNK" COMING FROM THE REAR OF THE VEHICLE IS NOTICED WHEN MOVING FORWARD FROM A STOP SOME TIMES. WITHIN A FEW WEEKS THE "CLUNK" BECAME LOUDER AND OCCURRED MORE OFTEN. IN ADDITION THE A LOUD "BANG" ACCOMPANIED BY VIBRATIONS WOULD COME FROM THE REAR WHEN GOING OVER SPEED-BUMPS. DURING THIS TIME THE CAR BEGAN FEELING UNSAFE WHEN ON HILLS OR IN THE RAIN. IF I WAS ON A HILL AND STARTED MOVING FORWARD I FEARED AFTER THE LARGE "CLUNK" A MAJOR FAILURE COULD LEAD TO THE CAR LOSING ITS REAR DRIVETRAIN OR SUSPENSION AND FALLING BACKWARDS. I ALSO FELT THE CAR WAS NOT SAFE IN THE RAIN AND THE REAR OF THE CAR WOULD SHIFT AROUND WHEN UNDER LOAD OR ACCELERATING. I TOOK THE CAR TO A LOCAL REPAIR SHOP AND WAS TOLD THE REAR SUBFRAME WAS TEARING AT MULTIPLE POINTS....