I know this is a pretty basic question, but I'm not very used to working on cars: my specialty is small motors and tractors. My brother left his Chevrolet Cobalt with me for repairs on the electrical systems. However, the Cobalt has been made for several years, and there are differences between electrical systems on the various year models. Unfortunately, he neglected to leave me the registration papers.
How can I tell which year his Chevrolet Cobalt was made in?