Oh wow. So, to get the figure after tax, you're multiplying by 2.8, not by 1.8? That's even worse than I imagined. I suppose that when we talk about a 6% registration tax in my state, that's unambiguously multiplying the end cost by 1.06, or 106% - but I'd assumed that they were inflating the figure by using the multiplier directly. That's astonishing!
Still, doesn't this also apply to the cheaper cars? You're getting a Pugeot 208 for not $20k but $56k. While the difference between sticker price and post-tax price is smaller in proportion with the cost of the cars - $63k vs $36k - that's still $56k... for a Pugeot.
On all cars, not just electric cars. That's sort of the point of the whole thing. Electric cars were taxed less than diesel or petrol powered cars, the law changed and electric vehicles started to be taxed as any other car and sales dropped like rock.