If your car’s antenna is not grounded, you will hear more static than music when you turn on your radio. The ground of an antenna needs to be attached to the car in such a way that the voltage of the antenna can connect to the earth. This connection allows the earth to receive and store excess voltage rather than the extra voltage bouncing back through your antenna and radio. It is harder to get a good ground on a modern car because of the way in which the body of the car is attached to the frame, however, it can still be done.
Open the trunk or the hood of your car, whichever is nearest to the location of your antenna. Locate the antenna ground. It is a single wire coming off the base of the antenna, not the larger cable wire that goes to your radio, but the only other wire running from the antenna.