Since scratches are your main concern, look for a paint protection film, also known as a clearbra. It's a clear film that goes over your panels, and it does a solid job against rock chips, light scratches, and swirl marks. You can cover as little as one panel or as much as the entire car (pretty common). Usually for people who are concerned with rock chips, the full front panels is a must. But since scratches can occur any where (especially if someone wants to be malicious), you have a few more panels to consider.