The secret is in the prepwork, .000 steel wool or substitute, 3m pad ect.
Be sure to remove the overspray film on the body (outside surface), mask widows then place blue, lowtack painters tape over the mask and trim, gently scour the entire surface to be painted with steel wool or pad, go easy around the edge of the masking, the pad is nice because you can cut strips to reach small spaces ect. wipe down body with a damp clean no lint cloth, let dry, check and go over any missed places, repeat until you have a uniform dull surface, prime with light coats x2 let dry overnight, mask and paint.
With this method, if you keep the surface clean during the painting process the finish will be more durable and last longer.