if these brakes were of the grey reyland ZS then they were fitted from I cant remember what car now, my head says the red devil ZS but I am not sure.
I fitted new discs and pads but they warped very quickly and it was given that it was the pad overheating (ds2500) cost me a small fortune.
They were great for day to day. When I took them on track they were a pain in the ass I could do about half a lap before bad vibration i mean really bad.
Anyway not sure what was causing it i sold the car but i am sure washers were used from the original setup and moved over.
hope you sort it
Ross
edit just remembered they were the brakes from Sam's ZS, he had bad scores on the inner disk caused by the lower arm nut, Pete gave me a link to reduced size nuts which i used with new discs and pads