Just for the heck of it, I reset my iPod, then reloaded all the music using a Audioquest cord with a 1/4 " ferrite core snapped around the cord almost butted up against the 30 pin connector that was inserted into the phone. I made sure all the music was encoded with Apple Lossless.

I snapped the ferrite core around the cable in the car between the Y portion of the Mini connector and my IPod. Treble cleaned up but sounded a bit weird in the midrange. Dissapointed with the result
I then snapped the ferrite core around the USB portion, not the audio portion of the Mini iPod connector that hooks up in the cubby area of the car. I heard a slight but very audible improvemt in sound quality this way.

Anyone who uses an iPod/iPhone as your source for music, give this a whirl. I've noticed stronger bass on all of the music as well as less sibilance (sp?) on vocals when the singer pronounces a word with "s" in it. The treble notes from the tweeters in the pillars sounds a bit smoother and less fatiguing. I also notice a bit clearer background with a slightly reduced noise floor.

I'm very pleased with the result.

I've got @ $6.00 into this little project and about an hour of time.

If anyone tries this, let me know what you think. If you have any other suggestions with placement of the ferrite cores, update please.