Can anyone advise the best time to replace the camshaft drive belt and water pump. I have been told by garage these need doing together? I have 2001 A3, done approx 95,000 miles. Service book says this needs to be done at 115,000 miles but garage is trying to convince me I should have had this done at 4 years old. Have just spent fair amount of money on new lambda sensor for engine management light, and also new altenator! The car is not due service till July 07 / 102,000 miles whichever is 1st, will it wait until then?