heh, a friend of mine was a congressman when they passed the guzzler tax. (yep, he was one of the sponsors) The idea was, the AGI (income) of those who drove passenger cars with low fuel economy was considerably higher than those who drove trucks with the same or lower fuel economy. So basically it was a money grab that had nothing to do with resource preservation. (global warming was not even a topic when they passed it) They also used to throw a "luxury tax" on the same cars just to make sure that we "pay our fair share".
So, I dutifully paid my GGT last month! Just another $1500 that won't go into the local economy!!!