I have noticed that the cpc is generally lower than sites in the health, gadget niche. Its surprising considering autos are very big ticket items and one would think advertisers would be willing to pay accordingly.
not all niche pay the same. all depends on whare you are getting your traffic from and what type of ads are being served
I have a car insurance blog and have a nice CPC and CTR.... I even got $17 for 1 click last November... Anything that has "insurance" on it is high CPC.