I notice, for the first time today, while just sitting in the car in the garage (was setting my home location) that I could hear something like white noise. At first I thought the radio was on and xm wasn't picking anything up in my garage (common) but the radio was off. All audio was off and the climate system was off. I hadn't actually powered up the motor, just the interior power so I could play with the nav system. The noise was louder in the front passenger floor board. I don't remember hearing it before, but it was fairly noticeable this time. I know with my Prius, it had random fans and noises it made even hours after turning it off. Has anyone noticed this or know what it is?