timbo thanks.
The build plate on my S60 says it was built in July 2019. So, that would make it a 19w17 ?
Looking at the lists on the Volvo web site, it seems that the number after the "w" is always a "17" or "46". Could that number be a release week ? I've attached an example model list.
it's all a bit confusing as the model list always has a year 1 year ahead of what's in the brackets e.g. 2020 (19w17)