Refinishing rear metal bumper on a Jeep Cherokee XJ. Typical AZ no rust, clean, faded finish. Do not intend to sand to bare metal but could happen in a few spots, just scuff with 320 before paint then pre-prep & tack cloth. What do you recommend in an aerosol primer & paint which will provide a durable finish resistant to scratching? Paint colour will be a satin black as was the OEM.