I think you are right about it being something with the brakes themselves. On top of the ISG being noisy, now mine is occasionally doing it when I put the car into reverse while on a very slight incline. I back into my parking spot at work every day, and it does it at least twice a week.However, for the first time the other day, I was stopped at an incline. The incline was steep enough where the car would roll back if I took my foot off the brakes. As soon as I took my foot off the brake to push gas, the sound happened again. Loud as hell and annoying as I remember it. So now I really truly believe it has nothing to do with the auto stop but with the brakes.