I'm in the process to launch a new website, focused on used cars in US. I'm starting this website more from curiosity, until now I avoided to create websites for US, because of a bigger competition. How well do you think adsense performs in US cars industry?
It depends on the content and the value of your site in the eyes of Google. Two sites with identical themes... take VW Parts for example could pay totally different amount. One might pull 2 cents a click and the other $2.00 a click. The formula Adsense uses to reward you is based on the value you create. In general the higher ranking site the more you will be rewarded. There is plenty of opportunity in the Automotive sector.
If your focused on Adsense, like everyone, I would create a highend used cars site and focus on related keywords, ie: used bmw cars or something like that. I think it would perform well with good traffic and design/placement.
Adsense earning totally depends on the niche. It is also dependent on the content of your site. Auto/Cars is a highly competitive niche so you really need to have a strong website to be able to compete with other sites.
Always focus on the quality of the content. If your content is excellent, you will most likely outperform other people in the same niche.