I have used these guys in the past, real good to work with, he answers his emails quickly and ships fast. Just send him an email of what you want and he will get it to you quick, I think what you want is the "superstripe" package but modified for a GT500 Cobra. V6 Mustang Stripes : BaltimoreStreetMods, 3M Automotive Graphics
These are his product, fit great and great quality too, look OEM for a fraction of the cost.