Something I have long wondered about...
...is why the other perpetrators are being constantly and consistently ignored in this. VW were only the first ones being caught, and were the first ones by pure chance--the road-test procedure used to check on-road emissions just happened to be tested on a VW Golf Diesel first, because the car was at hand. It could just as well have been an Audi A3 (OK, same company), a Honda Accord Diesel, or even a Jeep Cherokee.
Within a year of the original scandal, every single manufacturer of Diesel engines for personal cars in the entire world was caught red-handed. That includes U.S. carmakers, who are miraculously not being prosecuted. Or the Japanese. Or Italians, Or French. And every other German car manufacturer, including BMW and Mercedes, who keep enjoying good sales in the US.
An afterthought: the fuel injection systems and much of the engine control electronics for all engines found to be cheating were made by Bosch. Maybe that should be the place to look for the actual perpetrator?
Just a thought.