BMW Genuine 1 Series F40 M Performance Sills. Part number(s) – 51192462600 & 51192462601. Enhance the sporty aesthetics and aerodynamic performance of your BMW with the Genuine M Performance side skirts in high-gloss black. Designed specifically for optimal fit and finish, these add a dynamic accent to the vehicle’s side profile. Manufactured to BMW’s premium standards, it offers both visual impact and functional aerodynamic value. 1 Series F40 including M135iX.