These splitter side plates were developed in CFD and then wind tunnel and track tested to back up their results. On an average splitter, they will produce an additional 45-50lbs of downforce on the front of the car at 100mph and close to 110lbs at 150mph while only producing a few extra pounds of drag. They are sold as a kit of all 4 pieces (2 side plates and 2 tire deflectors). They come with rivits to attach to most splitters. Please check the measurement in the pictures to see if they will fit your splitter OR shape your splitter so our side plates will fit. Unfortunately we can not make custom size/shape side plates as the time to make a plug and mold is not cost effective for one off parts.