Glad to hear you've found the source. It would mean ideally you'd get new top mounts and bearings at some point, but it's by no means urgent. I sprayed WD-40 on mine about 5 years ago and still haven't replaced them. I'll probably do it this year, the whole front end needs a refresh.@ttg4l you were spot on, thanks.
I jacked up the front of the car, lifted the front sway bar a little, undid the screw and sprayed WD40.
Now all is quiet.
View attachment 53478
I'll do the outer tie rod ends and tie rod assembly at some stage.