A top German court ruled Monday that Volkswagen must buy back a diesel car it modified to appear less polluting, a decision that could influence outcomes in thousands of other "Dieselgate" cases. Judges at the Federal Court of Justice (BGH) in Karlsruhe "effectively upheld" a lower court's ruling that plaintiff Herbert Gilbert can return his car to VW for reimbursement but that he must also accept a discount from the original purchase price for the time he had used it. tgb/hmn/bmm