Page 12 of my service book says:
60,000 miles (
for the first time) and every 20,000 miles after - Toothed belt for camshaft drive:
check condition (only petrol engines).
Every 120,000 miles - Toothed belt for camshaft drive:
Replace (only for petrol engines with 5 valves per cylinder and 2.0l FSi engine)
Also in the "additional work" section of the service book, there is no mention of toothed belt for camshaft drive on a 'time' basis, either 2, 4 or 6 years...
No idea where the 4 years / 60,000 mile belt change idea came from, but that's what most people seem to think