I took my Audi Q5 TDI to the Garage for servicing and was told of heavy rusting on both sides of the rear subframe. The rusting is bad and can almost break the subframe It seems to be a known issue in Audi Q5 models, however, the dealership and Audi of America have refused to cover it as a manufacturing defect. The car has 88000 miles, and at this point, I think it may not be safe to drive. I am urging NTSB to review this issue and see if the issue can be resolved by the manufacturer at their cost.