By taxing at a rate that is greater than proportionate to use, you are
more likely to affect behaviour.

Except that it doesn't work. People who want to have big, fuel
consuming cars will pay for them.

Of course. To prevent that, you'd have to ban them, which I do not propose.
However, I would like them to pay much more than proportionally more. That
money I would like to see invested in CO2 neutral energy technology.

Also, it would deter a good number of people as well. Only the real petrol
heads will continue with a Group G car. Lots of people would be put off and
buy something less damaging.

Christian.