$4500 pumped into buying you a car is good for you, and slightly good for the environment; but investing $4500 into public transportation benefits hundreds of people, and is even better for the environment. Since we don't have much money, it's best to use it in a way that will have the most benefit.
Also, you yourself will always have the ability to use sidewalks and public transportation, but you will never get the ability to use a car that someone else buys.
I totally agree... but I can't help playing devils advocate when someone is very ardently against someone else's choices. Transportation is multi-tiered. In some places you need an automobile. They might as well be efficient.
