I've noticed on several GS's that one or both of the front brake rotors have a groove cut in them or worn in them. I've noticed that on several cars including mine. I'm not sure what the reason would be but sure should be one as many as I've seen?
I'm in the process of rebuilding the front end on my red 455 convertible. I've ordered drilled & cross cut delco rotors along withe KYB shocks new upper & lower A Arms.
Anyway just curious about the rotors