Quad Exit BMW 3-Series Touring (G21) Rear Panel DiffuserFits: Pre LCI G21 Estate Models with M Sport bodykit. This lower rear diffuser panel fits G21 Touring models and attaches directly to the OEM fitting points of the M Sport rear bumper. Specifically designed to be fitted in conjunction with the Cobra Sport quad exit performance exhaust conversions for the BMW 3 series. This lower rear diffuser panel allows the conversion of the G21 models to a quad exit exhaust system and fits directly to the OEM