Does any of it really matter?
Do nothing, and let the manufacturers charge way over the odds under the current tax settings, and people will continue to buy ICE vehicles. And, of course, get stung if/when oil does go North of $USD150 per barrel.
Or "help" the adoption rates by providing incentives to purchase (via reduced taxes payable on those vehicles). As I understand it, they do exactly that in the U.S, by providing Federal Tax rebates for those who purchase EVs and PHEVs.
https://www.fueleconomy.gov/feg/taxevb.shtmlIf, via a reduction in various taxes, the cost of an EV becomes comparable to an equivalent ICE vehicle, is it then "just" a tax break for the wealthy? Would only wealthy people buy the equivalent - and equivalently priced - ICE vehicle?
Sure. I get the "why should one vehicle be "subsidised", and not the other. Primarily, to encourage that shift toward an in-principle lower emissions private vehicle fleet, perhaps?
Because sure as eggs, if the current situation - including policy settings - remains the same, the "penetration" of EVs in this market won't rise beyond the current 0.5% of total sales in a hurry...