VW has been caught bypassing emission ratings by having a "defeat mode". The "defeat mode" allows cars to pass lab testing even though they actually emit 40 times the california emissions standard. (And I'm sure other emissions standards around the world).
At first it was only thought to effect 500,000 cars in the US market but as a cnn news article states (and many others):
"Volkswagen stunned investors Tuesday by admitting that the problem was much bigger than that: internal investigations had found significant discrepancies in 11 million vehicles worldwide.
The company set aside 6.5 billion euros ($7.3 billion) to cover the cost of recalls and other efforts to limit the damage, trashing its profit forecast for the year in the process.
Shares in Volkswagen ( plunged 17% Tuesday, after suffering a similar crash Monday. About a third of the value of the group has been wiped out in two days, causing big losses for major shareholders such as Qatar." )
Okay for people who own performance VWs this isn't really going to make much difference but people who did buy on a fuel-efficient, environmental basis this will effect them and no doubt the "fixes" provided by VW will most likely effect the car operating characteristics and feel which may make the car not at all like it was when the person bought it.
It also has tax implications in Europe where cars registration fees and environmental charges are effected by the emissions rating of vehicles. Probably the most galling is that it's broken one of the basic rules of business, "Don't sell a product that says it can do something when it most definitely can't"
The other odd thing to me is why Diesels are considered "environmental" anyway, more carcinogens and soot particles always makes me think that the "clean diesel" idea is kind of a misdirection. It's a bit like "clean coal" when what they mean is "Well it's cleaner than it was"
The good out of this is that one it shows that companies doing the dodgy will be caught and two there will be greater scrutiny of all vehicle manufacturers. I wouldn't be at all surprised if other makers were doing it too.