I had this, for me it was the bushes it had split I replaced it all was fine then it happened on the other side.
So I poly bushed the whole lot and now it runs and turns like a dream.
Double check the bushings just in case !
Just add I have read somewhere that early mk5 needed a steering rack replacement, I believe there was a recall !
Just finished a nightshift so il try get some info later, hitting the sack now.