[Pete.]

I believe that Denmark, and China are actively trying to discourage the use of cars because of their high populations. Hence the extreme taxes.

In Australia we do not have that problem, successive Governments of either persuasion just love to tax the shit out so called "rich" people. Hence luxury tax.
Also as Doug says it is rediculous trying to have a car manufacturing industry with a low population and very high labour costs.
Hence high import duty on foreign cars.