S6 c6 brake discs fit on RS6 c6?

[Kristianj87]

Need to change discs and pads on my 2009 RS6.
I see prices are horrible on original discs (390x36mm)
But I found out that c6 S6 (5.2 v10) discs is waaay cheaper. They are 385x36mm, so that souldnt matter, right? As long as they are identical in mounting core (sideways fit in the calipper? Anyone can confirm this right or wrong? Fits or not?

[CHEQUERED]

im would assume you will have 2.5mm over hang at the top of the rotor that would step the pads.

I know thats the case with other cars ive seen substituted with slightly smaller rotors.