The country that invented the diesel engine is having second thoughts. German courts have instructed several cities to limit diesel traffic so as to reduce pollution. In Stuttgart, Hamburg and Munich, downtown streets will be blocked off to vehicles that don't follow the so-called Euro-6 regulations by January of next year. Hundreds of thousands of car owners are affected. Our correspondents report on how locals are reacting.
A programme prepared by Patrick Lovett and Aline Schmidt.