My Porsche Boxster (986) 2.5 Tiptronic is now 13 years old and 70,000 kilometers run. Should the polyrib belt, the fuel filter and the air filter (would have been already at 40,000) be changed already now because of the age or is it enough if this is done at 80,000 kilometers? How does it look with the cost? Does anyone have a tip, who has done this already cost-effectively?