BMW M6 Gran Coupe car roof uses Hexcel's carbon fabric

PrimeTex is Hexcel’s patented technology for carbon fabrics, in which the fibres are spread in both the warp and weft direction, increasing the closure factor by 5-8% compared to conventional weaving processes. 

This results in a highly uniform fabric ideal for very lightweight structures requiring aesthetic appeal combined with high mechanical performance and very low porosity.

BMW claims on their website that the contoured roof effectively lowers the weight and centre of gravity of the M6 Gran Coupe for even better driving characteristics. 

Hexcel Corporation is a leading advanced composites company. It develops, manufactures and markets lightweight, high-performance structural materials, including carbon fibers, reinforcements for composites, prepregs, honeycomb, matrix systems, adhesives and composite structures, used in commercial aerospace, space and defense and industrial applications.

Hexcel