Trevora G42 M240i Carbon Fiber Rear Diffuser

The rear bumper of the G42 M240i is a performance coupe’s most visible angle at a standstill, and the ID-01 diffuser is built to make it work harder. The three-fin configuration draws directly from the rear diffuser language seen on BMW’s M coupe models, where defined fin geometry across the lower rear bumper has become a recognizable signal of performance intent. On the M240i, the effect is a rear end that reads as more purposeful and track-influenced without requiring the car to step outside its factory design identity. The fins are cleanly integrated into the diffuser body rather than appearing as additions to a base panel, producing a cohesive unit that sits against the factory bumper lines without disruption. From directly behind the car, the three-fin layout fills the lower bumper with structured visual interest; the kind of rear treatment that reads as considered rather than simply added on. Beyond the visual upgrade, the diffuser contributes to improved aerodynamic management beneath the rear of the vehicle. The fin geometry and diffuser profile work with the airflow exiting under the car, reducing turbulence and contributing to a more stable aerodynamic profile at the rear end.

Carbon Fiber Construction

• Constructed using high-quality autoclave-cured pre-preg carbon fiber for superior strength-to-weight ratio. Each component is engineered and prototyped in-house using advanced CAD modeling and 3D scanning to achieve precise factory-plus fitment. A UV-resistant clear coat protects the clean weave pattern and maintains finish quality over time, ensuring long-term durability in both daily driving and high-performance environments.

Features

• OEM+ fitment – engineered specifically for the listed BMW platform
• Pre-preg autoclave-cured carbon fiber construction
• UV-resistant clear coat finish
• Superior strength-to-weight ratio versus wet-lay carbon
• Direct OEM fitment
• Plug-and-play installation
• Backed by Trevora’s industry-leading 5-year warranty

Included in Box

• Carbon Fiber Rear Diffuser
• Required mounting hardware
• Installation instructions

Applications

• BMW M240i: G42 | 2021-present

Frequently Asked Questions

• What vehicles is the TREVORA ID-01 rear diffuser compatible with? The TREVORA ID-01 Carbon Fiber Rear Diffuser is designed specifically for the 2021 and newer BMW M240i G42. It is designed for the M240i rear bumper configuration. Standard G42 2 Series models use a different rear bumper and fitment compatibility should be confirmed with Bulletproof Automotive before ordering.
• Does the ID-01 diffuser require cutting or modification to the factory bumper? No. The ID-01 rear diffuser installs using the factory bumper mounting points and OEM clips as primary attachment hardware. No cutting or permanent modification to the factory bumper is required, and the installation is fully reversible.
• How does the three-fin design affect the aerodynamics of the M240i? The three-fin diffuser geometry works with the airflow exiting beneath the rear of the G42 M240i, helping to manage turbulence at the rear end and contribute to a more stable aerodynamic profile. The fin configuration draws from the rear diffuser approach used on BMW M coupe models, where defined fin geometry is used to direct and separate exiting underbody airflow more effectively than a flat lower bumper panel.
• What is the design reference behind the three-fin configuration? The three-fin design references the rear diffuser treatment seen on recent BMW M coupe models, where multi-fin diffuser geometry has become a defining visual element of the M performance aesthetic. The ID-01 applies this language to the G42 M240i, connecting the model visually to the broader BMW M design direction while keeping the overall result within OEM+ boundaries.
• Does the ID-01 diffuser integrate with the rest of the TREVORA ID-01 program for the G42? Yes. The ID-01 rear diffuser is part of the TREVORA ID-01 exterior program for the G42 platform, which also includes the ID-01 front splitter and rear spoiler. All three components share the same design language and are developed to work together as a cohesive exterior package.
• What is pre-preg carbon fiber and why does it matter on a rear diffuser? Pre-preg carbon fiber is manufactured by pre-impregnating the carbon fabric with a precisely controlled resin ratio before the component is formed and cured. This produces a more consistent weave pattern, better structural integrity, and a higher-quality surface finish than wet layup carbon. On a rear diffuser with three integrated fins viewed from directly behind the car, surface consistency and weave alignment across the full panel are directly visible; pre-preg construction ensures both.

About Trevora

Trevora (formerly TRE) is a UK-based automotive aero and styling brand specializing in high-performance pre-preg carbon fiber components. Founded in 2018, Trevora has grown into a globally recognized name in BMW aftermarket parts, known for its OEM+ philosophy, precision engineering, and uncompromising attention to detail. Every component is designed, engineered, and prototyped in-house using advanced CAD modeling and 3D scanning to achieve precise factory-plus fitment. By utilizing autoclave-cured pre-preg carbon fiber, Trevora delivers a superior strength-to-weight ratio while eliminating inconsistencies found in traditional wet-lay carbon. All products are backed by Trevora’s industry-leading 5-year warranty.