Another point of view, and be sure to read the comments.
Fox found two whiners complaining about being lied to because the car isn't "clean", but I'm betting most people with one don't give a crap about that and isn't why they bought it. I'm sorry, (not really) but I'm laughing. VW obeyed the letter of the "law" because it said the car had to test "clean" ----- and it does.
I'm inclined to think this has a lot to do with it - "EPA is mostly an agency used to control markets, not pollution."
As most crony capitalists are hand in hand with statists...the comment above is the partner to my quip about missing a payoff. But tabling the issue of a missed payoff it is easy to see why a bunch of statist clowns would see body-slamming a foreign-owned car maker as a ploy to direct (so they stupidly hope) more business to Obama Motors. That the EPA slammed VW indicates to me they perhaps were not on the VW payroll to start with...and I doubt VW is the only outfit trying to scam the Fedcoat goons.
I guess I never saw a benefit to a diesel passenger vehicle, especially in this climate, the F350 dual-axel my BIL has is a horse and it works well pushing a snow plow and hauling heavy trailers...but it has to have the engine heater plug connected in winter to keep the block warm. No doubt there were subsidies and other promo's going on with these passenger diesels and the fart-sniffers who wanted them blindly went about their smugness if it factored at all.
If this mainly affects assclowns in EPA-PsuedoStates like California don't expect me to give a rip! 
It would have been better for VW (or anyone) to avoid this Prog-driven eco-market crap and let domestic crony outfits bungle in it. If that meant writing off CA sales, so be it!
I think it is funny what they did, but we all know Progs and Fedcoats have NO sense of humor...and will exploit anybody for their own gain no matter what. Knowing there is a trap is the first step in avoiding it. I would have chosen not play this game.
As to the emissions crap and performance issues, I know for fact that certain after-market devices can be used to boost horsepower etc, I'm sure the trade off is even worse fuel efficiency, how that affects the emission crap I don't know nor does anybody probably care. Last I heard nobody was going after these after-market producers...though that probably is going to happen the deeper we descend into statist tar pits.
The EPA has been going after aftermarket producers quite a bit lately. Several have paid millions in fines and some are now out of business as a result. Its still legal to remove emissions equipment for off road racing, but nothing else anymore. So many kits are sold as race only, off road, wink wink.
The DEF tank is something that would have never otherwise been added to diesel vehicles but by government edict. The DEF fluid is used to inject unburned particulates back into the combustion chamber to burn them up. It robs from the engine, horsepower and decreases mileage (by quite a bit in some vehicles), so in many ways, it probably doesn't actually decrease emissions because your burning more fuel overall, and getting less power, and some as a result will buy a bigger engine to cope. Its one of those "it sounds like it helps" but in reality is bullsh*t.
It also decreases the advantages of owning and operating a diesel vehicle. You lose mileage, you lose power. It increases engine complexity (diesels being more simple then gas) for buyers, which increases maintenance and repair costs. The emission equipment is well known for it unreliability (even on new vehicles) and high cost of repairs. It may not be a big deal for the first owner of a diesel truck (under warranty), but when that truck is 15 years old and on its third owner, its going to be a big deal, as it will be a big repair bill for the person least likely to be able to afford it. So between the high costs of repairs and the basically unknown results of 15 years of burning the particulates in the engine, the diesel engine may lose its well known longevity.
So a delete DEF kit may be the most economical choice for many buyers. They get the horsepower and mileage back, and you don't have the engine ruined by emissions equipment.
Its part of the government war on older vehicles (5-20 year old vehicles that is) and the people unwilling to go deeply in debt to be driving a new car all the time. They have a problem now that the average car doesn't rust away by its 5th birthday anymore and that a ten year old car is often got many good years left on it. So it's add this bullsh*t equipment that makes it cost too much to keep that old truck.
Keep in mind, over the last 30 years, the pollution from cars has decreased by 97%. The average 2010 car pollutes 97% less then the average 1975 car. In some ways a huge success. HOWEVER all the low hanging fruit is long gone, and that last 3% is going to be the most expensive to try to remove. But the government wants it anyway, even though it doesn't really do anything. Keep in mind when they say they will reduce emissions by 30%. That 30% is a fraction of what is really 3%. Economically stupid to bankrupt everyone trying to get it.
