the best way? get factory black panels, i dont care who you are, paint will scrape or flake eventually and will never look the same as a true black panel. end of story. unless you want some color not offered why not just get the real deal. Paint only what you HAVE to.

I did mine and my girls interior (profesionall since thats what i do) sprayed adhesion promoter through a gun and ppg paint through a gun and they both looked great and you could take a key to the platic panels and not scratch the color off, and I had a spare panel, that i tested on and after about 10-12 months the paint began to scratch easier. Trust me it will let up at some point.