You are right that a car can make it cheaper/easier to live at a certain standard of living. However, some people can't afford to live at that standard of livin

You are right that a car can make it cheaper/easier to live at a certain standard of living. However, some people can't afford to live at that standard of living at all and have to make do without the lifestyle improvements that they could have if they had a car. Hence, having a car is a luxury.