I used to have the Vorsteiner bumper with CSL splitter cutouts and fog lights. The fit was probably 90-95% on the mark but I could tell it was not OE. In an effort to get a OE fit I ordered a Euro front bumper and had the cut out for the splitters molded to match the Vorsteiner bumper. I have had this on the car for about 4 years, which is going to be replaced by an OE CSL Bumper. I did order a OE CSL diffuser which I have had on the car for years.