I replaced my Positive Crankcase Ventilation (PVC) valve on my 2.0T FSI S3 (8P) tonight, which not only resolved an issue where the car was idling rough at 800-900RPM and hunting up to around 1300RPM, but it restored a fair bit of boost, improved engine response and smoothed out performance when letting my foot off the throttle. Very happy indeed. Especially as it was a five minute job for anyone who can turn a screwdriver!
So anyways, the handy info I have are the current part numbers, as supplied to me by Southampton TPS (a.k.a The Trade Parts Specialists). These guys are the most professional supplier of OEM parts I've dealt with. Many of the garages/workshops in Southampton get their parts from these guys. That's how I found out about them. Anyway, enough friendly promotion. Here are those part numbers:
PCV valve cover assembly: 06F 129 101 P = £32.24 inc VAT
PCV valve cover gasket: 06F 103 483 E = £16.78 inc VAT
PCV valve cover to turbo hose: 06F 103 215 B
PCV tube to turbo metal gasket: 06F 145 757 F
I actually only bought and replaced the PCV valve cover assembly and the PCV valve cover gasket (always best practice to replace gaskets and seals when replacing the associated parts), which came to less than £57 inc VAT. But if I remember correctly, all four parts would've come in at around £80. Considering other older revisions of the PCV alone on eBay were shifting for £45 inc postage, I'd say going to Southampton TPS was a much better choice. I hear they're pretty good when it comes to returning parts you might've bought that were not correct for your car.
Hope this info helps someone.