| Hi Jordan
From your description " rust on the bottom" it would appear that the car was stopped and water dripped or was splashed onto half the disk causing temporary oxidation. Like Keith I would like to see a photo as it does seem odd.
Long time since I was at school but after years in the workforce one thing I've noticed is unprotected metal exposed to moisture oxidizes or becomes discoloured .
My wife drives like Mike and I drive sportier (like Keith almost) and disks are shiny.
Bill F |