Just for the record cars are not "manufactured globally" cars are manufactured on specific countries which then have long logistics of acquisition, not all countries make cars and the ones that do can very certainly be pushed through legislation to make "smaller cars", as this problem is specifically poignant on the United States changing united states legislation would have a large footprint by itself in the same manner that air quality standards of California have nearly become international standards for all vehicles

That said there is no political will for this to happen, therefore it won't, which is sad given that is a good idea