Originally Posted by DimSum
But your still replacing the hub/rotor whenever you get a brake service at BMW. As long as your brake assembly is not rusting it's okay.
Yeah, it's a superficial rust, but it's ugly, especially on a BMW.
I guess I didn't use the CORRECT term...
When I said HUB, it's the protuding piece on the brake disc.
The OEM brake disc is one piece.
It's not that expensive if you just want to replacement. People have been painting them themselves.