Rust on brake rotor "hat"?

[Canuck]

Dave
soaking that part of the rotor in evaporust will remove the rust,but it involves removing the rotor. There are brush on rust neutralizers that would work if left on over night. Once you decide what to do, use LPS or boeshield on that part of the rotor to preserve it. Depending on how many miles are on the brakes, you may be replacing the rotors soon. Most German cars rotors are throwaways with each brake job.