My rear brake rotors were close to the maximum thickness, so they had virtually zero wear other than rust and other deposits that had accumulated over time. Instead of replacing them and since the rear brake rotors for the S1 Esprit are unique (that also means expensive!!), I decided to have them resurfaced. The job was relatively cheap ($40 USD) and there were many local shops capable of doing it. I blasted the surface rust off the center of the rotors and then repainted them, and the ring plate which goes between the brake rotor and the gearbox mounting plate was yellow zinc plated.