If you are set on keeping your 2015 Mustang stock grille, or even want to pursue other aftermarket possibilities, you may want to keep this modification in mind.
The 2015 Mustang’s stock grille looks great but as with all things straight off the line, can be further optimized — in this case for better air flow which can have benefits for air cooling and aerodynamics.
A few M6G members have been cutting the grille inserts and have been reporting the ambient versus IAT temperatures to have improved between 1-3 degrees. Of course, several aftermarket grille delete options exist in the aftermarket, including Dusold Design’s hexagonal upper grille kit which one member reported to have similar benefits. But if you want to keep the stock grille and willing to put a little elbow grease into it, this modification may be right up your alley.
See the modification in the FORUMS.