the upper scoops or air extractors didn't require much modifying .just a little enlargement of the mounting holes in the front two an the rear mounting holes. the scoops actually allowed air out of the car ,they were blocked off in the front inside. they were hand laid fiberglass and rough on the back side. the pair i have are real Shelby. the mounting tabs were simply flaps of fiberglass and used the same J clips as the front fenders. three bolts from the inside of the car mounted the scoops /although i have seen scoops with another in the upper middle and using bonded on studs instead of bolts .mine have three bolts . the scoops off the blue care were the early scoops and had the red lights mounted in the rear of the scoop,sorry i don't have a pic. the easiest way to tell if they are the real thing is the rear opening is smooth all the way inside. aftermarket scoops have a joint line where the inner piece is bonded to the outer shell.