A paint run appears when heavy application of sprayed paint does not adhere uniformly to the car's surface. This is often due to using the wrong paint thinner or an excess of paint thinner. Runs in new paint can be seen once the paint has dried completely. They can show up on any part of the car. You can repair paint runs without repainting the entire vehicle.
Move the car to direct sunlight to see exactly where the paint runs are and ensure that these areas are thoroughly cleaned. Make sure the area is clear of dirt and debris.
Wet a piece of sandpaper and gently sand the run smooth. The clear coat will appear dull once the spot is uniformly smooth with surrounding paint job.
Rinse the car again to remove all debris. Let it completely dry.
Apply the rubbing compound to smooth out any imperfections.
Polish all sanded areas until they shine. Polish the entire car for a deep shine.