Carbon fibre or fibreglass, what is the difference?

Both are composites: fibres in a resin that together are stronger than either on its own. Carbon fibre is stiffer and lighter for the same strength, and the weave looks good on show. Fibreglass is less stiff and slightly heavier, but considerably cheaper and better at absorbing impacts. We choose per part: carbon where stiffness and weight matter, fibreglass where robustness and price weigh heavier.

In our open air intake for the A6 C8 too, we apply both materials where they are strongest.