I have no idea where its coming from really. Sounds like from the dashboard or engine area. I hear it when inside the car at idle speed. When you press the gas pedal sound disappears. It's a clicking sound that is fairly regular. It can't be heard from the outside. I've shut the heater off to confirm its not the fan or hvac system and the sound is still there. It seems as though there's so many issues with the 2010 outbacks.