German Auto B - BMW M440i Diffuser Composite Carbon Fiber

This rear diffuser is designed exclusively for the BMW M440i, giving the car a more aggressive and high-end rear profile with a full carbon fiber construction. Built from a high-quality multi-layer composite with a tempered finish, it delivers a deep carbon weave, strong rigidity and a premium motorsport look that transforms the back of your 4 Series instantly.

Produced in our partners’ factory with advanced carbon fabrication techniques, the diffuser is lightweight, extremely durable and weather-resistant — ideal for daily driving in Canadian and US climates. The fitment follows the exact shape of the M440i rear bumper, ensuring a precise, secure and seamless integration.

This upgrade sharpens the rear bumper design, enhances visual width and gives your M440i a clean performance style with a true full-carbon finish. If you’re unsure about compatibility, send us your model, year and exhaust setup — we’ll confirm it for you.