Here's a quick update to this thread, as one of the links has changed.
I've just done mine, and most of the above was spot on. For my 2013 van, a Mk6 Golf style MFSW wheel worked well - part number 3C8 419 091 C - which you can get with just the MFSW controls or with the DSG paddles as well if you want. With that wheel the original airbag fitted no problem.
The loom from airbag to steering column needed replacing, and 3C8 971 584 F was the part needed, but check carefully as there are at least a half a dozen variants of this part - with a different letter at the end - and you (obviously) need the one with exactly the right connector types.
The guide that I followed was this one (which is the one listed earlier, but they have changed the domain name):
6R - Multifunction Steering Wheel Retrofit - UK-POLOS.NET - THE VW Polo Forum
Yeah, I know, it's for a Polo, but the only real differences I found were wire colours - the pin locations all worked fine for me.
The main wiring difference on mine was that the wire on the BCM (white plug T73b, pin17) was blue/green and not violet/white.
As an alternative to taking a power supply wire for the steering wheel slip ring (T41, pin9) from the lighting switch, I used the existing supply for the Cruise Control on the same connector (T41, pin28) which on mine was a blue/black wire. The advantage of this is that it's an ignition switched supply which already has an appropriate fuse (Fuse SC9, 5A) and it requires no fancy cable routing - it simply loops round behind connector T41 on the back of the slip ring. The disadvantage over a permanent supply is that the controls stop working when you turn the ignition off - for me that is not an issue! However, if your van did not have CC from the factory there will probably be no such wire and no fuse at SC9.
Coding changes were minimal (I think I made 2 coding changes as referred to in the Polo article, plus the change for "push to talk" which does nothing for me, as I don't have factory bluetooth). I bought the wheel with DSG gear change paddles and these worked with no coding changes at all. The right "up" and "down" MFSW buttons call up the basic DIS display but that is minimal - it just gives basic MPG, range and trip data. I don't think it's possible to get anything more than this without a Highline instrument cluster upgrade.
If you're costing this up for a DIY job, don't forget the outrageous cost of the tiny airbag loom - mine cost me a shade under £50, UK retail. The wheel itself was £160 including shipping from Germany, so total budget including the 2 repair wires was roughly £220.
It took me a whole, long day - but I work slowly so that I (usually) don't break things. There's nothing fundamentally difficult but there are quite a lot of trim bits to remove/replace - it's not a job I would want to have to hurry...
