I own a Porsche Forum and run some discrete Google Adsense ads... The others are in my VW social community... www.iVdub.com and between the 2 it takes a few months to earn $100 from Google. Anyone want to look over my sites and provide a little suggestion to increase the revenue, would be much appreciated.
I looked over it briefly. I have one suggestion, take out the link ads and put in text box ads. The reason being, link ads are harder to earn with. Users have to make two clicks, as opposed to text box ads where the user only has to click once. Plus, without the text box's ad copy, users may be less inclined to click the ads.
How much traffic you getting? I would imagine a car site, especially one dealing with a luxurious car like Porsche will have ads that are pretty high paying even though the ads will probably also show ads for other types of cars as well. On the whole, I know couple of people that run car forums and, even though their CTR is low, they have high CPC to make up for it.