Dave, German engineering has been greatly overrated from the end of last century onwards, lots of Mk3 Fabia, at least, have noises from the underside, some owners have changed some parts with success whilst others change lots of parts over time at great expense and still have noise(s). My wife's 2015 Fabia has a very noticeable clunk/clonk from about 6 years old, that was after the two front dampers had to be changed (and one of the new ones was "misting" within 11 months (2-year warranty), still on the car now and still a MoT advisory. I (luckily) don't drive the car very often but last winter when it was very cold I couldn't believe how loud the noise was, and I'm used to 20-50 year old cars' suspensions, all better than the 9 year old VW product! As put you do need to check your suspension is in reasonable condition (for a VWŠkoda Fabia of the age) and of course safe. Drop links and other bushes are favourite to replace, dampers or springs assemblies are also possibilities, other causes of course (exhaust, other). My wife's car has been through 4 MoTs since the noise started, one with VWŠkoda Dealership, another with an independent and two with a decent old-fashioned garage (they don't work weekends, imagine trying to explain that to an under-50!) and I ask them to check the suspension for parts that need changing sooner rather than later, they don't use the same dampers that the VWŠkoda Dealership use as they so short-lived.