2003-2005 so C5 I think.
It's win win, the TTRS chaps are uber weight sensitive, even with the adaption there's no weight increase, the disc are directional and sort of floating.
Even though it's a heavy casting, the OEM 310mm disc won't take much heat so you're sort of limited to a DS2500 pad really, the better disc allows RS29's in essence the next group of pads up.
The TTRS caliper carriers are required they're different to R32/S3 ones