Philosophy Free from the compromises of series production, AC Schnitzer develops custom components to the highest standard of perfection. “Form follows function“ - This guiding principle is systematically applied by the engineers and designers of the aerodynamic components for BMW vehicles. AC Schnitzer aerodynamic components pick up and subtly emphasise the styling lines of the base vehicle, while giving the body striking new contours. At the same time however, they have a real effect: They increase downforce on the front and/or rear axles, to ensure better ground adhesion. Only high quality composite materials, such as PUR or carbon, are used in production of our AC Schnitzer aerodynamic components. Because only these materials meet our high quality standard. Material: Polyurethane (PUR for short or also known as PU) Thanks to its outstanding mechanical properties, PUR (polyurethane) is ideal for use in areas exposed to high wear, e.g. in quality vehicle construction. PUR is easily formable, very form-stable and very light in comparison with other plastics. It also paints extremely well (even repeatedly, where required). Polyurethane is produced by a chemical reaction that takes place immediately before the material is processed. Polyol and isocyanate react to form polyurethane in a mixing head. PUR obtains its positive product properties through processing as "PUR Integral Hard Foam". Thanks to its very good static properties, it is particularly suitable for technically demanding moulded parts and self-supporting products. The wall thicknesses of these parts are slightly thicker, but the ratio between strength and weight is still excellent. As a rule, the reaction mixture from the mixing head and sprue is filled into a closed aluminium or epoxy resin mould in which it hardens to form the moulded part. PUR Integral rigid foam is particularly impact-resistant, tough and elastic, yet flexible and abrasion-resistant. The resulting aerodynamic components are deburred, ground and - as a special service provided by AC Schnitzer to simplify handling for the customer – primed. Once primed, AC Schnitzer aerodynamic components can be painted to the customer's preferences in any conceivable colour by a local paintshop of the customer's choice. Creative Design PUR, ASA or Carbon: at AC Schnitzer, all draft designs originate from a true Italian artist: Michele Viandante, who has been Head Designer here for many years. Naturally his designs are not only beautiful but must prove their suitability: for example, many parts are function-tested in the wind tunnel. Testing If the calculations match the results, further tests follow. For example, crash tests using dummies confirm that pedestrian protection requirements are fulfilled. Only when all tests have been passed and the homologation certificate has been issued are AC Schnitzer aerodynamic components released for sale worldwide. Homologation Certificate The parts homologation certificate is an official document which allows the use of tuning parts in public road traffic within the framework of the (StVZO) German road traffic licensing regulations (and some other countries). After installation or conversion of the part described in the certificate, the vehicle must be presented to an official inspection body. The inspector determines the correct installation and the authenticity of the part and subsequently enters the modification in the vehicle documents. The official operating license of the vehicle thus remains in force. The parts homologation certificate is part of the scope of delivery. Scope of delivery: - rear roof spoiler, primed - vitro sticker - vehicle specific mounting package - mounting instructions incl. painting instructions - homologation certificate Uniqueness of the rear roof spoiler - enhance downforce on the rear axle - sporty desgin - Made in Germany - made of high quality PUR - weight optimised - easy painting and mounting - long lasting - developed exclusively for BMW 4 series Gran Coupé (G26) - 2 years warranty