Unless your goal is a Roush look-a-like, don't feel pressed to put all roush on the car. IMO, as long as you stay away from pieces that have the name badged like the roush rear bumper, shelby brand grill or lettering like shelby for the rear deck lid, then mix and match to get exactly what you want. I haven't completed my car yet but I do have the Cobra GT 500 rear bumper and spoiler but then I put SHR louvers in the qtrs and I'm adding a cervini nose and hood on the car. It makes it unique and your own without copying a single mfg style.
Looks good so far
LB