One of the best methods, without the risk of scrubbing, is to slather a bunch of leatherique on the wheel, cover it in a plastic bag and let it sit in the warm sun for a few hours. Clean the residue off with pristine clean. Results are amazing and the softness, not only the matte finish, is restored as well as protected. I know it has a higher cost than some products, but you can get the set on amazon in the 16oz size, which is enough for the entire interior, not just the wheel.
02 E39M5 | TiAg/Schwartz | Tubi Rumore | Ultimate Ti Pedals | E60 SSK | Jim Blanton 3.45 40/100% | Coby Alcantara | StrongStrut STB