If you run your hand over your car's surface and it feels rough or gritty, you have paint contamination. It happens when tiny metal shavings land on and adhere to your paint and then start to rust. You cannot remove these shavings by washing or waxing your car. You could use an abrasive cleaner, but this won't fully remove the rough spots. Instead, you can use a clay bar to pull out the contaminants before washing and waxing the car.
Put the car in park or first gear and lock the parking brake before turning the vehicle off.
Thoroughly wash the car with the sponge, car wash solution and water. Be sure you have removed all surface grime and dirt. Allow the car to dry thoroughly or dry it by hand.
Follow the manufacturer's instructions to apply the clay spray lubricant and use the clay bar. Spray about three feet of the vehicle at one time. Run the clay bar back and forth across the lubricated area until the surface is smooth to the touch. Dry the area with a clean cloth before moving on to the next area.
Pull and stretch the clay bar to expose a "clean" surface to use on the next section of the vehicle.
Polish or wax the vehicle as you normally would once the entire vehicle is dry and the surface is smooth.
