BMW 4 Series Gran Coupe G26 Pre-Preg Carbon Fibre Rear Diffuser Set by FORM (2021+)

Sharpen the rear profile of your BMW 4 Series Gran Coupe G26 with the Pre-Preg Carbon Fibre Rear Diffuser from FORM. Combining aerodynamic function with aggressive styling, this diffuser bolts directly in place of the factory unit for a clean OEM+ finish.

Key Features:

• Direct OEM fitment — retains factory mounting points, wiring connectors, and sensor cut-outs where applicable
• Autoclave-cured pre-preg carbon fibre construction for a consistent 2x2 twill weave and show-quality clear-coat finish
• Aggressive vertical fins add visual width and motorsport presence
• Improves underbody air extraction for reduced rear lift and improved stability
• Direct-fit replacement for the OEM lower rear bumper section
• Backed by FORM Industries — a trusted name in OEM-level aftermarket upgrades for modern performance cars

Materials & Construction: This component is produced from genuine pre-preg carbon fibre — the same autoclave-cured composite process used in Formula 1 and OEM performance parts. Unlike wet-layup or hand-laid alternatives, pre-preg delivers a tighter, more consistent weave, superior strength-to-weight ratio, and a show-finish gloss clear coat with full UV protection. The result is a part that looks as good in five years as it does on day one.

Fitment: This product is designed specifically for the BMW 4 Series Gran Coupe G26, model years 2021+. It integrates with the factory panel lines, mounting points, and (where applicable) electronic systems, meaning no cutting, drilling, or bodywork modification is required for a standard install. Please double-check your chassis code against the listed fitment before ordering — if you're unsure, our support team is happy to confirm compatibility for your exact vehicle.

Installation: Fitment is straightforward for an experienced installer using standard hand tools. We strongly recommend installation by a qualified bodyshop or detailer, particularly for exterior components that require panel alignment, adhesive bonding, or painted-surface preparation. Full fitment guidance is provided in the box, and our support team can help confirm the best approach for your specific car.

Why FORM Industries: FORM has built a reputation among serious owners of BMW, Audi, and other modern performance cars by obsessing over the details most aftermarket brands skip — panel gap tolerances, UV-stable finishes, genuine pre-preg composite processes rather than cheaper wet-layup shortcuts, and in-house fitment testing on real cars rather than CAD models alone. The result is a range of parts that install like factory equipment and hold up the way factory equipment should.