Thanks for your input guys.

I did a bit more "troubleshooting" - just trying to narrow down the causes/circumstances.

It happens for both left and right turns and the more I listen/feel it the more it seems to be mechanical in nature. Only happens in first gear. I did try turning the traction control off and still happens. The suspicious sound/feeling comes on even with the slightest amount of acceleration.

I did a bit of reading and possibly the haldex controller? I tried finding something on Youtube to compare but didn't really find anything useful. There does seem to be quite a few causes for the sound though so seems like I get to begin my journey with VW maintenance/fault finding which doesn't fill me with the greatest confidence...