I have noticed that the collar section of my discs , I think in the US you call them rotors are rusting. The front discs which were recently replaced ubder warranty are fine no sign of rust on the brake disc collars at all. I am going to take the wheels off and clean off the surface rust, off the collars of the brake discs. Can anyone suggest the best paint to use which would match the factory finish. I do not intend to use spray but would like to brush paint them. I take it the disc collar gets hot, so would I need to use a heat resistant paint? Its a shame that BMW doesnt take a little more thought about the cosmetic look of its brake parts. I know this is purely cosmetic but rust looks crap through 19 inch alloys.

 

I have the same issue on my Porsche. I guess due to the grade of steel used that it is still prone to rusting. It is said that the wheel cleaning agents someone uses contributes to this.

There were a number of other posts regarding 'rusty hubbs.'

 

This is very common problem in Estonia also. Reason for that in here is we use salt to melt snow.

 

thats right, this can cause it.

i get this also, its a common problem