Patrick George:

 Volkswagen admitted to cheating on emissions tests with 11 million TDI engines worldwide, but are they alone in this? That’s what regulators and NGOs around the globe are trying to figure out at the moment, and at least one European group fears BMW, Mercedes and General Motors are doing the same kind of thing.
 Discrepancies between real-world diesel emissions and what they record during testing in Europe have been an issue for some time, but the issue hasn’t really caught traction until VW’s gross flouting of regulations came to light.