I've been a longtime rally fan; Since I was a kid my favourite cars have been 80s Group B and early Group A cars. A characteristic of the most famous Lancia Deltas of these eras (S4, Integrale) were these black "wheel protectors" that were occasionally attached to the wheel rims, but I could never find an explanation to their purpose. I presume they're either to keep dirt off the brake rotors, or they're an air channeling device to direct air into the wheel to help with cooling, but I could never get anything confirmed from Googling. Could a Lancia connoisseur please explain what these actually are? I included some photos of what I'm referring to. Cheers.