@User9609 I think you actually bring up a good point about the whole thing. Most people don't understand the emissions issues. When buying a car colour is probably more important to a lot of people, it's new, so you believe it complies to everything, be that safety features or the latest EU levels.
Emissions does play a part, but I'd say to most people only as part of 'how much VED will it cost?' and 'how economical is it' - practical stuff that will cost you money to run it. With a new car you're not likely to worry about whats coming out of the exhaust until it comes round for it's first MOT, 3 (and possibly now 4) years later. And even then it's likely it will pass with the probe up it's exhaust from local test station - the US limits where it all started are lower than ours and the official tests are done in lab conditions.
Diesels are a lot cleaner, even without the fraud, than they used to be. Wonder how much it's balanced out though with the push there was for diesel cars and there now being a lot more of them on the road.