I've a VW Polo 1.2 E with the 55bhp 3 cylinder engine, AWY series. It's approaching 40,000 miles and I've been told by the dealer that the "cam belt" should be changed. I presume that they, in fact, mean the timing chain. I also contacted an independent Volkswagen specialist for a quote, and they say that the timing chain should last the lifetime of the engine and needn't necessarily be changed. So what should I do? Is the timing chain normally changed at 40,000 miles?

Many thanks.