I've also made a vector graphic of the Corley Motors logo. It's probably not 100% accurate, but I think it's pretty close. Here's a preview:
Here it is to download as an EPS file:
http://rapidshare.com/files/203382403/Corley.eps
If you would like to make a shirt, I would suggest something other than CafePress. Their shirts come out fuzzy looking. There are better alternatives on the web, just search around.