A seller may agree with the buyer that the buyer has no rights because of defects. Section 444 of the German Civil Code sets a limit. The seller cannot rely on such an agreement soweit er den Mangel arglistig verschwiegen … hat, insofar as he has fraudulently concealed the defect. A seller acts fraudulently when he knows of a defect, or thinks it possible, and deliberately leaves the buyer in the dark. The Regional Court of Potsdam stated the duty plainly. The seller of a used car must reveal an earlier accident ungefragt, without being asked. Only minor damage is exempt, and a replaced fender no longer counts as minor.