When car was in reverse and starting to move, there was a clunk noise, I thought I hit something , also a slight shudder on Acceleration from take off. Took to dealer thinking it was transmission, they did computer update, clunk still occurred, car back at dealer, come to find out there is a bulletin, if there is a clunking noise, replace rear differential, on the report it states, clutch pack fault, replacement of rear differentia , at 47k I'm afraid to drive this car after warranty with all the other problems we have had.