Am I correct in thinking that the cam belt or timming chain ( think it's one of these's) needs changing after 4 years regardless of milage. The car is a 1.2 12v 3 pot Silverline Estate on a 53 plate with 25k on the clock ( December 03 ) or Is it a chain, not a belt therefore does'nt need doing ........Thanks

The 1.2 3-cylinder is chain cam, so ought not to need replacing unless / until the noise drives you nuts. However, according to 'Honest John'

Timing chains of 3-cylinder chain cam petrol engines are snapping, possibly because they need cleaner oil than VAG anticipated with its service regime, or possibly because the wrong oil has been used. Timing chain tensioner problems on 2002-2003 1.2s, usually caused by not changing the oil and filter often enough. Cured on later engines by a more substantial tensioner.

So, while there's every chance you'll be OK, it's maybe worth getting the service history out, and/or getting it looked at just in case...

Sorry for the indecisive answer!