The other thing to consider, is that if the discs are out of spec (thickness) and really need to be replaced, there is a possibility that your driving style may have contributed. The front brakes as you know should be doing the lion's share of the work when slowing or stopping. But PSM (even when switched off) will continuously intervene on the rear if you are not very smooth. This can contribute to rear disc wear.

Also, many will recommend that the rear pads be checked very frequently, as pads that are worn just 50% will tend to wear the rotors faster than new pads. If your pads were very worn before your track days, you may have added additional wear to the rear discs.

But again, I would recommend a formal brake inspection before spending $$$ replacing the PCCBs with aftermarket steel rotors or other. I do not believe that the "wear circles" alone are a reason to replace the rotors.

bob

 

another high quality option for replacement rotors is with Stoptech DRK.
I know GMG sells them. slightly more $$ than the GiroDiscs though..

 

The Stop Tech works great!! We also offer Brembo