I never noticed this before in the last 3 months of ownership, but it's so low I wouldn't even know if it was there. Today as I was pulling into my garage I noticed a very very faint beeping sound from somewhere in the interior of the car. Because it was so low and intermittent (one faint beep every 10 seconds), I couldn't quite place it. Car drives fine, no dash lights on, no interior lights on, door is closed. This was when car was off and on w/ engine running. Couldn't find anything in manual... or in the search on the site. Any thoughts?