I have a '98 Jetta with the factory Panasonic head unit and CD-Changer. I have noticed a low frequency hum from the speakers - noticeable during silent passages on the CD, tape or FM - when the headlights are turned on, but not with the DRL's. It makes no difference if the engine is running or not. Anyone else notice this problem? Might just be a bad head unit. Thanks. Steve ssutton@ridgenet.net