[corebreach]

I have a similar problem and am having a lot of difficulty solving it. My iPod is connected to my truck via an XtremeMac Roadshow Car A/V cable. It combines the line output and charging input on the dock connector into one cable. It Y-splits into RCA connectors and a cigarette lighter plug. The RCA audio is plugged into my Pioneer deck's AUX input. When the cig lighter plug is plugged in, I get electrical interference (hard drive, processor, etc.) from the iPod transmitted through my speakers. The problem goes away when my iPod is not plugged into the truck's power outlet.

Here's what I've tried:
In-line audio ground loop isolator between the iPod and the deck input - No effect on the noise
Snap on ferrite core kit on the power wire from the cigarette lighter plug -No effect
Snap on ferrite core kit on the audio wire from the iPod to the headunit - No effect

If anyone knows of a solution please let me know, I hate having to unplug my iPod to listen to music without the noise!