highwaywonderland

I wonder if anyone can tell me what this might be, ONLY when its cold (like 45 or below) when I am driving at a low rate of speed and am only barely pressing the gas pedal (like 25mph) the car makes a buzzing sound. If I press the pedal down a little harder to start accelarating rather than a constant speed it stops. I don't notice it any other time when it's warmer out. Could it just be something condensing cause it's cold out and rattleing. It sounds like its coming from in the front of the car. maybe even down where the gas pedal is, should I even give a rat's *** about it? I don't notice any perfomnace difference. I noticed it last winter as well, but forgot all about it until now.