I think you should bring more attention to the navigation. While it is bolded, and has :: seperators, it still could use something more. Perhaps a background color alteration should do the job. Ideally I think that orange you used in the header would look good. G'luck!
It looks bad to me....bad background color http://www. chinacarforums.com /forum/ one of the worst i 've seen
I agree with the background color. Try something more neutral like grey or black and see how that works
Tidy the home page layout at the very least: Put a colour strip under the navbar, or just invert it so it stands out from the page. The ads need to have a one line spacing from the navbar, like they have on the forum page. Refit ads at bottom to fit on line. The image and query box could be aligned better. I like the big headers. Forget rules. Those cool cars demand it.
I have a problem with sites where the content starts half way down the page as this one does, so I would say, yes the top banner is too big.
i think bigger banners help convert better, but since i dont have as much content on each page, i thought big banner more attractive
I would suggest making your "Mission Statement" shorter in length. I rather read too little information than too much.