Then wipe the area with pre-cleaning solvent to remove any wax, grease or tar. Make sure to cover sections that you don't want to paint, like chrome trim and light, with masking tape. When dry, wet sand lightly again until the surface is smooth. Then apply the primer, making sure to fill in just the repair spot without going over onto the paint. You can then spray the paint that matches the original car color from an aerosol can.
Aerosol paint is available at auto supply stores.
Apply several thin layers instead of one thick layer. Start from the top of the job, spraying from left to right until you reach the bottom. Each coat should dry about five minutes before applying the next coat. Once you've applied the final coat, use a polishing compound on the area you've painted as well as surrounding areas. This will merge the colors.