This analogy would've worked much better if you just stuck with the rural Texas thing. The problem is that, to most people, a "car" is an essential need.
Look at it this way. There's an essential amount of money people need to get by, right? Everything OVER that line is "extraneous" in a sense.
In some areas, a car is a necessity to get to work. A cell phone might be a necessity for work. Clothes, food and shelter are obvious, etc etc.
The rich pay more in taxes simply because they can afford to. Let's assume that there's a flat tax of 10%. Who do you think will feel the crunch more? The person making 100,000 a year who now only takes home 90,000? Or the person taking home 30,000 a year who now only takes home 27,000?