[Idaho2018GTPremium]

If this is for a ZL1, GM's engineers have stated that the front plastic bumper cover (the black piece behind the grille that covers the actual bumper bar) was designed in a wind tunnel, and essentially makes the bar invisible from an aero perspective, so it's like its not even there. So, there's no need to remove it for cooling or aero perspective. I can't remember which site I read it on, but it was legit.