Hum, I just got an idea. Could be horrible, but I'll run it by you guys to see what you think.
What about every vote is weighed based on a calculation of the number of posts the user has who is voting and the rating of the voter's car themself. For example, woobie would have a heavy weighted vote because he himself has high rated car, showing his good taste in car moding, as well as the active members of the site having more say than the less active members. This way if someone signs up a new account and votes lots of people a "1", it won't do much because they almost no weight (low post count and no car rating).