This is not possible in market capitalism. Companies will produce as many cars as people will buy. Even if one company decides to restrict its production, another will fill its place. You need central planning to decide how many cars are to be built, and to be sure, if you look at the centrally planned economies of communist countries, they definitely did produce less than third the number of cars their citizens enjoy now.

> You need central planning to decide how many cars are to be built

Isn't it what every non-banana-republic is doing already, indirectly [0]. And if we get serious about achieving net-zero economy and price carbon accordingly the car makers will have to adjust even further. They could plant trillions of trees, or they could make fewer cars. Up to them. I am just saying that in my view making fewer cars will be a more viable economic decision. And consumers will redirect their purchasing power to something else.

[0] https://en.wikipedia.org/wiki/Vehicle_emission_standard

> Isn't it what every non-banana-republic is doing already, indirectly

Emission standards do reduce number of cars produced, to be sure, but much less than you propose. Mostly what they do is make the cars kinda suck, especially compared to how expensive they are. People buy cars anyway, and put up with it.