As I'm in the process of having the handbrake shoes replaced on mine I took a look at the condition of the discs. It seemed they have quite a lot of rust build up on the surface due to irregular use of the car.....I tend not to use the car for a couple of weeks then give it long runs etc. Seems that moisture causes the rust build up which doesn't then shift because there's nothing removing in day in day out as per a daily driver.
The rear discs/pads I changed at 137k miles and they've done 18k miles , not that great but I guess this is my fault as much as anything. The brand of the disc was Bremtech and pad Mintex. I wasn't ever fully convinced by this disc/pad choice (cost was £260ish all in which did seem a bit cheap) and got the impression they warped a bit over time as they seemed to be a bit juddery under progressive braking. My advice would be to avoid Bremtech.
So knowing I had to replace them I then set about reading up on disc/pad choice and believe me there is much written on this topic. The main school of thought suggests that you can run Porsche discs on the standrad RS2 brake set up (from a 944 Turbo or 928 I believe) part numbers are given on S2 forum. The latest post suggests the Boxster discs would also fit. I took a look at these (they are drilled but not vented), they are the correct dimensions (299mmx24mm but cannot be sure that the bore hole is the correct size? I believe this should be 130mm? Can someone confirm? Manufacturer of the ones I saw were Zimmerman (this brand gets good reviews on S2 forum) and were going for what seemed a bargain price of £150. Perhaps worth taking a punt on these if you are fitting these yourself, you could always sell them on if they didn't fit.
But again there appears to be much indecision as to whether these really are a direct replacement and as I'm not doing the work myself I decided to forget that idea in case it turned out to be incorrect. I seem to remember Scilly and Alistair G summarising that OEM were the best choice after much debate.
However, the OEM discs on the RS2 were Brembo and they are now on back order from Audi. Price quoted was £640 for rear discs and pads (ouch). I have managed to find a set of OEM these at a much more reasonable price so fingers crossed they will arrive safely. I've ordered the Brembo pads to go with (£60 for a set on Fleabay) so it'll be interesting to see how this will affect the braking. New brake fluid all round will do no harm either.
Just wanted to share this as I wasted many hours yesterday trying to figure it all out and effectively came back 360degrees to where I started
Will post back here once I've tested the new set up.