After proving their worth on the track, natural fiber composites are finally making their way into BMW Group’s production cars. Years of R&D and testing have paid off—these renewable materials have now reached what’s called “series maturity,” which is industry speak for: they’re ready for the real world, not just racetracks.

Developed in collaboration with Swiss clean-tech firm Bcomp, these flax-based composites tick all the boxes—including the tough homologation standards for structural parts like roofs. BMW’s been working with Bcomp for years now and even invested in the company through BMW i Ventures, which tells you just how seriously they’re taking this whole sustainability push.

Lightweight construction has always been a BMW specialty, and this new material not only cuts weight but slashes CO₂ emissions in the process. Swapping out traditional carbon fiber for flax fiber in the roof of a next-gen model can reportedly cut production-related CO₂ by around 40%. That’s before you even get into how much easier this stuff is to recycle or dispose of.

The first testbed for this tech? Motorsports, of course. BMW M started using natural fiber parts back in 2019 with its Formula E program, and the M4 DTM and M4 GT4 have since followed suit. Since 2022, Bcomp has even been an official partner of BMW M Motorsport.

Next up is the real proving ground: the 24 Hours of Nürburgring, where these materials will be put through hell on the BMW M4 GT4. As BMW M boss Franciscus van Meel puts it, “Natural fiber composites are a vital element of innovative lightweight solutions in motorsport.” Translation: they’re fast, green, and about to go mainstream.

And yes—true to BMW M’s slogan—what’s born on the track is about to hit the street.