Squeak from rear brakes

[Carbon VW]

Hoping someone can shed light on this very annoying squeaking! MK7 GTi no noise when start car first with windows open. After about 10 minutes of driving there is a high pitched squeak coming from the drivers side rear wheel, especially noticeable when travelling at low speeds through a town. Sound disappears immediately upon braking and returns after. When I park in the garage after daily commute, i can slightly rock the car forward/back and hear the noise coming from the rear wheel. Discs and pads were both changed about 15,000km ago and are in fine condition with no signs of wear on the discs. I have removed the pads, re-applied anti squeak to the pads, lubed up the slider pins and checked the backing plate, everything look fine. Its driving me mad, hopefully someone can offer some more wisdom. Thanks.

[madstaff]

Have you checked to make sure the pads are free to move in the carriers??

Could slip the pads out again and just sand the face of the pad (which rubs on the disc) on a flat surface with some coarse sandpaper just to remove the shine on the pad surface.

[Carbon VW]

Yes have checked and they are freely moving. The sliders were still well lubed up from the last pad change.
Will remove again and try sanding the face of the pad..

[madstaff]

Just thought, you havent caught the metal shim which the pads slide into and dislodged it/bent it and its now touching the disc??

[Carbon VW]

Just thought, you havent caught the metal shim which the pads slide into and dislodged it/bent it and its now touching the disc??

No, checked that when I had the wheel off last week to put on winter wheels. Its a weird but annoying one