Hello all. My 2015 e-Tron has developed a fast ticking sound, which disappears when the brake pedal is applied - or even barely touched. My dealer quoted around £2K to replace the whole brake servo assembly, but advised against it as there is apparently no record of this being a problem. It sounds to me like a relay or servo - something electrical - so I was wondering if anyone else had experienced this? Or has any advice? It seems crazy to shell out that much when there may be a company who could refurbish the unit, maybe? Thanks.