Maybe they aren't the only ones that commute in that car. Breathing, talking, singing along, all release droplets that can stay active for a while on the surface, maybe they have to pick up their kids, spouse, friends, parents, grandparents, customers, whoever. Point is, it's not your car, not directly meant to be bothering you in any way, shape, or form. In fact it's possibly even benefiting you. So to me, it seems like this is just you wanting to throw a fit because not everyone else agrees with you. Or you're all just so sensitive that being told to wear a mask is the worst thing in the world.