spudgun:

This story will hurt VW very bad. Cheating enviromental tests, how low can you go? enlightened Must be a PR nightmare.

The administration has used a fat thumb approach for some automakers versus others.  For evidence, look at the way the administration handled Toyota versus its ongoing work with General Motors equipping cars with keys that would fall out of the steering wheel lock.  

Another interesting point is the EPA doesn't have the resources to "find" this level of deception so the word probably came from another automaker on the violation of the emission standards for the diesel vehicles.