>people who can typically afford to drive anything they fancy ... reasonable use of an incentive
No it isnt.
> Lets also not forget that these are the people whose tax revenue supports everyone else - so perhaps they for once deserve the same break that everybody else gets
i.e. you rob them to pay them back??? that makes no sense, least of all probably to them - they'd probably just prefer less taxes
yes, government is necessary and there are many cases where market forces on their own do not achieve desired outcomes. but any time the government collects money, some of that money is bound to be lost in collections, management and disbursement costs. that's dead money and does not benefit anyone except for public sector employee payrolls.
so you want to target subsidies where they're really needed. not fluff in useless ones like luxury vehicles.
in fact, one big problem with global warming mitigation is that politicians are way too fond of subsidizing instead of just taxing emissions, since it's so much easier electoral-wise.