I know at least 2 people that bought new cars because the road tax was free or £20 , they laughed when I bought an impreza with its £500 a year road tax and 25mpg fuel economy
One is paying out £200 a month, the other has spent £1000 on a new DPF , 2 years down the line both have lost a small fortune in depreciation, my impreza is worth 90% of what I paid for it 2 years ago.
They both fell for exactly what the government wanted, they changed their cars which generates vat in big lumps and now phase 2 of the plan is coming into effect they'll be paying the same or more road tax as they did on their petrol cars.