put the global warming BS down our throats and most of the general public thinks its a good idea to tax big cars...
personally id scrap road tax but increase fuel duty to like double or whatever. That way the people that do the most mileage pay the most, not the ones with expensive/rare cars that dont drive them much at all....
The thing is that normally be the sensible thing to do, however the UK never seem to pick this up and decide to do something completely pointless.