I just had my rotors replaced at the dealership after 53,000 miles. They should be OEM parts (any advice on how I can confirm}. In addition to the main drill holes, there apears to be a number of smaller partial drill holes in both front and rear rotors. On one of the front ones, this hole is quite deep and very close the the edge of the disk, which seems absolutely wrong from an integrity point of view. See pictures below.
Does anyone have anything similar on their rotors? Any advice? I am thinking of taking it back ….


Front rotor

Rear rotor

Those are wear indicators. Nothing to worry about. Once they disappear the rotors need to be replaced.

Ah - thanks, that now makes sense. Explains why I didn't see them on the rotors i just replaced!