it is coming from the rear of the car...near were the sub woofer AND rdm are located. Friends couldn't hear the sound from the outside though...and the sound only starts @ 3 MPH and really sound digital, not like a gear and there are no vibrations and the pitch seems to change drastically and then go quiet consistent with speed but not with load/force. It sounds to me very similar to the input that influences the pedestrian awareness system...just wondering if a short could provide power or feedback to the sub woofer for the exterior fake robot sound that goes to the two exterior speakers. I know our cars make different sounds than most others but I just don't think this is something mechanical sounding. I'll go see if I can find the fuses, etc. and try to turn off sub woofer. It just started after charging up this morning, out of nowhere. I'm getting no change in performance, etc. I REALLY HOPE IT'S NOT THE RDM!!!! That was already swapped out before I bought the car.