I've certainly reduced my tourism levels on account of CBP. Can you not rip my car to shreds every time I cross the border?

if you took cars away from the entire population that would only account for up to 25% of the CO2 being released. So, on this small a scale it's doing almost nothing.

A 25% reduction in CO₂ is a massive undertaking the likes of which have never been attempted before.

And yet it still is not enough. Not to mention that banning car usage will disproportionately affect poor, disabled, rural, and mentally ill people.