I have a 1999 C70 2.4 that recently picked up a squeal during left hand turns at speed.
Between then and when i stopped using the car it became louder and even started to occur on the straight ahead (but not when turning right)
It seems to happen at speeds of over 50mph and when the car has warmed up (though of course it could simply be that it takes for me to reach the motorway before the car comes to temperature.

When it first happened I assumed it was brake pad wear indicator, but pads and disks are all fine.

The MOT certificate has two advisory notes that state that both ball joints had play at the time of testing (Jan)
So I'm assuming that I should check the state of these first, possibly to replace. Though out of curiosity does anybody know if the ball joints are sealed or are you able to lubricate them?

Also does anybody have any further routes of investigation I should take?

Thanks in advance

Nath