As far as I'm concerned, if the car's done 30k and is 6 years old, it needs a cambelt change, no questions asked. My friends TT had it's cambelt snap- the manual recommended only mileage and said nothing about age. His cambelt went before it was "due". He successfully got £1500 out of Audi as they should have included this information in the service book, or contacted the previous owner (who was his sister from new) that there is an error in the service book.
Belt(s) MUST be replaced at a 6 year gap regardless of mileage (or if car does 90k first, even then I'd change it a little before to err on the side of caution).
.........................that said, I just checked, my 12 year old clio hasn't had a cambelt change, getting it done for my little sister when she passes her test
