In the USA, at least, cars are a status/phallic symbol and thus are larger and/or more powerful than they need to be in a practical sense.
You can apply that same "phallic symbol" to anything; I think of it when I see people showing off all their Apple crap every time they sit down. Saying things like that is an easy way to get people all worked up ("America Sucks, It's all their fault"), but that's all.
I drive a small car (average 33-35MPG) for my daily commute, but I need a larger car to move things and construction materials to work on my house. Why should I be punished for that?
I use it for work as well, but who is going to decide what is an allowable exemption? You? How much use does it take to be legitimate business use? Why should large families have an exemption, they are a big part of the problem. We know what causes pregnancy now-a-days. Frankly, we should tax large families because they take so many more resources.
My large SUV gets 21MPG highway, though I average about 17 with city driving. That's better than a Volkswagen bus, should they not be taxed even more for wasting more gas? Or is it all about the appearance of the vehicle, like when I traded a Chevrolet vehicle for a Toyota and was congratulated by friends, despite the fact that (1) the mileage was about the same, (2) the Toyota had to be made in Japan and then shipped over with considerable fuel use. They did not care; American brands were bad for the environment, Japanese were good. Logic does not come into it.
And why should people be able to buy gas-wasting AWD Subarus? Most days of the year, even in snow country, you don't need AWD, yet it wastes a lot of gas. They should be taxed for buying a feature they don't need. And bike racks on the cars, they really increase wind resistance and lower mileage, that should be taxed. How about people who drive miles every weekend to participate in marathons and other runs? They don't need to do that, they could sit at home or take a bus. They should be taxed for wasting fuel. A lot of pollution is generated by ski resorts, we should tax them for wasting energy, tax them even more if they care caught running lifts that are not 100% full (they should stop the lift unless the seat is taken). And nobody needs to ski, we should tax all of those people for wasting gas to drive there, and triple-tax them if they fly!
Where does it end? And who makes the decision? The power to tax is the power to destroy.
Oh, and high-end sports cars already pay a "gas guzzler tax".