The difference was the clips on the very front and back are different for the standard and ST skirts. They mount to the car the same but the mount on the skirt for the clip is different. Not counting that, it's a direct swap with no extra parts needed.
2012 Yellow Blaze Focus SE Sedan (DD+Project)
1992 Bright White Grand Prix SE Sedan (Project)
SR #74/SMk3C #17/YBOC #03