Unban kei cars. Cars are cheaper if there’s less car.
Build more public transport (particularly trains, electric of course) so more people don’t need cars, then tax ICE cars heavily
Make all greenfield street grids use narrow streets (that means a max width of 6m(20ft) wall-to-wall, for 80% of streets) and over time convert existing grids likewise, which (strongly increases pedestrianism and) encourages any urban car drivers to drive kei cars.
If most drivers of big cars are rural, then let the big ag subsidies cover it. Although honestly, if urban drivers stop driving cars (and ~80-90% of people are urban (that includes suburban)), then we’re 80-90% of the way there anyway, and the last 10% doesn’t matter.
Point 2 and 3 would require major political buy-in (and they’re also sort of the same step anyway), which strains the definition of possible. But it’s quite financially feasible.
Depending on your definition of “possible”:
Point 2 and 3 would require major political buy-in (and they’re also sort of the same step anyway), which strains the definition of possible. But it’s quite financially feasible.