Conflicting evidence out there regarding recommended service life of PD timing belts. Autodata recommend 40k miles or 4 years, Tecdoc data supplied by Contitech (who are OE supplier of belt to VAG) recommend 90,000kms. Word on the street suggests VAG have bulletined dealers to change at 40k miles or 4 years. Local dealer says 4 years or 60k miles, local VAG specialist also says 60k miles or 4 years. Any factual evidence not hearsay appreciated!!