My '13 has the mount on both visors. I keep my sun glasses on the driver's visor. BTW, there are other accessories that you can buy for those spots. Look at the Ford accessory site. I believe it's all in the owner's manual for you edification.
Performance White '13 v6 MT. 3.55 gears, Bama tune, Eibach sway bars front and back, Airaid CAI, Boss 302 STB, 18x9.5 SVT wheels, 255/45 ExtremeContact WD tires, Redline hood struts, various appearance mods and FUN.