Just purchased the engine cover and put it on today. Thing about it is that it is soft and flexible. Like a thermal foam. So I'd worry that if painted it would crack if you needed to remove it.
2013 Mustang V6 w/Premium Package, Comfort Package (Yay pony lights...), Appearance
Mods: Airaid CAI, Ford Racing 3.73 Gears, Aluminum 1-pc driveshaft, American Muscle Staggered Black Bullitt 18" wheels, Bama Tunes, Ford Performance engine cover, JLT Air/Oil Separator, Boss 302 Strut Tower Brace