lol Richy, was a rather vague unhelpful response now that I find out I can't find that post either!
I've had a good hunt myself Gibbsy and you're right, it isn't there! It did have a pic from AndyMac so I'm wondering whether they have deleted it in their spring cleaning as the pic was prob hosted on audisport's server.
Ok ...! Did you have a standard Audi stereo in your car to start off with? If you did then on the sticker it should say which it is.
I can't remember which wire it is 100%, but it should be easy to find as 1 or 2 of the connectors are for the speakers, the other one is for the DIS and then i'm pretty much sure that the other connector houses the VSS signal along with the power connectors (best checking on that!). If you have a multimeter then you can check that the wire you think it is ain't going to do any harm (ie VSS wire should not be a continuous 12v!), the input to the stereo is probably protected anyways so should do no harm.
So best thing to do is to have a look at the sticker on the head unit, which shows the wiring diagram. From memory of andymac's picture, the VSS connection is easy to see, if not take a pic and post it back on here.
I'll have a search on bentley forum as pretty sure I read it on there too!
Hope this reply is much more helpful than the first vague one!!!!
P.S. It's snowing and I'm in work!