S550 owners looking to add the aggressive RTR signature styling while improving air flow to the radiator may want to look at the 2015 Mustang RTR grille.
Designed with original OEM CAD data from Ford and made of injected molded TPO material, the RTR grille has the added benefit of improved engine cooling while looking pretty good in the process.
M6G member Project Whitemare (Nick) give us a step-by-step walk through of his installation of both the upper and lower RTR grilles on his Oxford White 2015 Mustang GT with performance package.
See the 2015 Mustang RTR grille installation in the forums.