Hi I know there was a thread on this 2 years ago but it had no conclusion and Im experiencing the same problem. When I press or let off the brake i can hear some kind of electronic or pressurized noise. This also happens when i accelrate out of the auto hold brake. I took it to dealer and compared with the st i test drove and it was doing it as well, though not as loud. Dealer says its an actuator? Does anyone know if I should be trying ti get the dealer to fix this? Or does anyone else know what this is?