Hello Tom,
Good to hear you are concerned to do the right thing in respect of cambelt changes.
A couple of questions:- What date (year) was the belt changed when the mileage was 75K?
What make parts were used at the last change- Audi, or aftermarket (what make if so?) and was the water pump changed at the same time, and if so, again what make?
Kind regards,
Gareth.