When I purchased the car 7 years ago I complained to the main dealer who sold me the vehicle that there was a noise during acceleration; usually heard when pulling from below about 2000 revs. The car had about 23,000 miles on the clock. The dealer said it was due to a vibrating heat shield over the exhaust and I believed him. The car has now covered some 107,000 miles. The noise has become louder to the extent that I would probably find difficulty selling the car. It sound like a noise from the transmission; I don't think it is the heat shield. Can anyone suggest a possible reason for this noise? The car has never given me any trouble and has always performed well.