the comments had some good stuff: yes, shouldn't be per-manufacturer and no caps, but maybe don't OVERLY punish late entrants by giving them maybe an extra grand or two of advantage.
It also should not apply above a certain price point, or phase out above 50k.
It should phase out 1k / year, and there should be a phase-in of various ICE taxes: gasoline, car registration (so you get used cars), and new ICE cars.
I also think that there should be a very rapidly expanding tax on any ICE that isn't a PHEV, and that the qualifying all-electric range should climb 10 miles per year starting at 25 miles. PHEVs will maximize battery supply and is the low hanging fruit for reducing emissions, if it is true that 80-90% of trips can be covered by 30-50 mile range.
