My dealer contacted me at 4 years (180DSG) this September. Having given me a ‘special offer’ of around £300 including free (!) MOT, when I got there to book in the service man reckoned it would be foolish not to go with water pump and other gubbins as well for £500+. Strangely, the free MOT was no longer included (well, it was eventually).
It felt like a classic case of ‘bait and switch’ (get the customer hooked on one thing, then slip in something more profitable). So before you go in, decide exactly what you’re going to go for.
I checked with VWCS who said, based on my vehicle chassis no., that 4 years is correct for the cam belt.
I think the precise timings are anyone’s guess - there may be an engineer in Germary somewhere who has an idea, but for the rest it looks like conjecture.
Still, I personally know of two cases of failed cam belts - the petrol engine just rolled to a halt, but the diesel ate itself as the pistons hit the valves.
So don’t sweat it too much, you need that cambelt.