if it doesn't have one then your not required to put one on (at least not in nevada) Just leave it off, unless your state requires that you add one for an added cost. i love the look of them without, I say leave it that way.
2012 F-150 EcoBoost 4X4 (work truck)
Focus S #1, Sedan Revolution #192, Rally Revolution #8, March 2012 SOTM
Focal Distortion, a Ford licensed club and FSC member.
Sgt, USMC (1999-2003)