My 2006 Volkswagen Golf GT diesel 170bhp has just had its second service, as it's on long life regime. While booking it in, the dealer remarked that it will need its cam belt changed in November when the car reaches four years old. The mileage is only 36,410 at present and I'm curious as to whether this is normal, as I was led to believe on average it's around 100,000 miles until a cam belt change.