Studying race-prepped factory or shop-backed cars is a side hobby of mine. One thing keeps coming to my mind as I look at these cars : Why is expensive carbon fiber being used in unnecessary places? Given that the general method of laying CF is the same as fiberglass, is that CF dashboard really needed?

The often-seen door “cards”, specifically, have me very confused about the spending of some teams. First of all, what is the purpose of interior door trim in a race car? It’s either purely cosmetic, provides a barrier from sharp door interior workings, or both. What’s wrong with low-grade 2mm aluminum stock as a skin? How about plastic or even cloth-like N-mil plastic sheeting (think extreme-duty contractor garbage bag material)?

It’s quite possible I’m ignorant or naive, but is carbon fiber really the proper material to make a WRC handbrake from? I have to believe that an amazing lightweight aluminum piece could be CNC machined from billet for half of the material and labor cost.