Europe used to be mecca for diesel cars, but then VW went and ruined it for everyone. In response to VW's Diesel-gate, European regulators are proposing rules targeting diesels with more strict regulations and higher possible fines.
Reuters reports that these stricter guidelines could all but kill off diesel cars in Europe, which would effectively kill off the diesel car in all markets. With America's reluctance to buy diesel cars due to their old school reputations of being dirty (A reputation not helped by VW's recent scandals), Europe were the last mainstream marketplace for these cars.
With the rise in popularity of electrics and hybrids and possibility of stricter regulations, we may be witnessing the death of the diesel car.