Quoted from Anim8ormatt:rustoleum semi gloss black. It's almost perfect to my eyes.
For filling small cracks or scratches, I use an acryilic paint pen from hobby lobby. Not a sharpie. Sharpie pens and paint pens have a slight brown cast.
Acrylics dry with a flat look, did you use a clear afterwards? i have some glossy black acrylic paint and did exactly what you mention on my sides of cab fillin cracks and you can see it not as shiny and stands out when the light hits it at certain angles of view!