I don't think you can vote twice, or not in quick succession from the same computer. Certainly, when you open the page, you always see the option to vote, and you have to "vote" to see the current scores, but when I did that, the top of the bar said "Thank you, we have already counted your vote" - and the vote tally did not increase.
It's pretty standard to make sure one IP can only vote once. I'd have been surprised if it had been different. Anyone who has more than one computer could always do a vote from each though.
The GTi seems to be equal third at the moment.
Rolfe.