I live in a small town, will that affect my chances of being selected?

Your exact location doesn't matter as much as your driving habits do. If you live in a small town but drive 50 miles per day on a busy highway, you will have a better chance of being selected than someone living in a large city that doesn't drive many miles. It is all about exposure and how many people will see the vehicle. It is ultimately up to the advertisers as to whom they select.