With 147k on the clock I booked in for a new clutch, good job I did as the week before it was due to be changed it wouldn't clear - had to stop it, put it in gear and restart it in gear to drive it to the mechanic!!
Anyway, I get it back, clutch is fine, but there's the noise that everyone else has described.
After a few checks and tweaks - screws were missing from bumper to wheel splash guard and steering grommet wasn't quite back in correctly - I checked the forum and tried switching the air con on and off, yep, the noise came and went as the a/c was on and off.
To cut the story short, I took it for a regas - there were approx 170g in the system, there should be around 750g - the noise instantly disappeared once the system was filled.
I reckon it was around 3 or 4 years since it was regassed (mainly due to COVID) so just shows regular regas is needed, in fairness it was still working even with only about 1/4 of what it should have in.