I just purchased and had installed stoptech slotted brakes for my is350 and noticed a weird wear on them. I noticed it once it rained and they rusted up a little. Theres a small almost half inch like of rust that doesnt go away making me assume that chunk of the rotor doesnt ever get contact with the rotors? It seems off to me but i have no honest clue

 

Yes, normal for uncoated rotors. Some brands offer a ‘coated’ version which would have those areas painted or plated to prevent rust. It’s mostly for appearance, that they be coated. Rotors will function normally as is.