I've got a 2011 CDTI. Tracked the squeal to the nearside rear wheel.
I knew it wasn't wheel bearing or pad related because it was the same pitch regardless of wheel speed. And intermittent.
I removed the brake pad carrier and shook it violently. There was the sound. Basically ( in my case ) the handbrake cable has a ball on the end that sits in a small bracket on the back of the Carrier. The ball is getting on a bit and showing signs of weathering along with the bracket, showing rust lines down the bracket. I greased the ball where it sits in the bracket ( because I had the car on axle stands with the handbrake off the ball had freedom to move slightly in its enclosure allowing enough space to let the grease get at it.
Problem solved.
I'll be honest, it'll probably be back again soon when the grease wears off but I reckon I'll just replace the handbrake cable and grease the new one on install.
Some of you may have the same issue hope this helps.
