If you look at the original Rieger Infinity skirts you will notice that the upper edge is shaped according to the car they go on (eg; 2 or 4 door). It makes fittment a lot more difficult IMO, and you have to get the right one for your car. Back in the day i used to cut off that upper edge (lip) but now i have modified the molds so that they are straigh, and they fit any 2 or 4 door without any mods!