If you're in a rush to do a project like this, you could end up getting frustrated long before you get productive. To get a wiring project right, you need plenty of information that can be hard to get, even with good resources like a Bentley manual and VCDS. There's a lot of good info out on JSWs with MK VI electronics in this forum, but for the MK V JSW, things are a bit different. Fortunately, it's very much like an '09 Jetta at the same trim level...so an SEL (2.0t) JSW is much like an '09 GLI.
One thing I wanted to do was to set up a rear fog light. Much of the info I found on the JSW forum was for MK VI JSWs. MK V or MK VI, setting up a rear fog light involves moving the wire for the driver's side fog light to another position on the CECM and recoding. For the MK V JSW, C12 goes to B4 and then you recode. The driver side back-up light needs to be changed to a red light bulb, too--unless you buy the (correct) Eurotail light.
So after some research, I got started to doing the swap, but I realized that I was supposed to tap C12 for a signal to the back-up camera. I guessed that C12 would go dead when the CECM got recoded. So I had to consult an expert (Maloosheck) to see what I should tap. &
Turns out that B1 is the passenger side back-up light, so that's where the BUC harness gets hooked up. If you're going to set up a fog, I'd suggest tapping the passenger side back-up in all cases, since it would make rear fog activation so much the simpler to do.
The BUC also needs a constant (but fused) power source from the battery. The MK VI uses position 17, but that's filled on my MK V JSW. Position 16 is open and works fine, though.
These points are relatively easy. I'm now stuck trying to sort out CAN-bus controllers because VCDS can't see the RNS-315. I'm coming to the realization that I'm likely to have to buy a new controller.
That saga is playing out on the VDCS tech support forum here: http://forums.vwvortex.com/showthrea...s-and-Retrofit