I had just recently bought a Sirus receiver for my car and came to realize that it had that same annoying high pitched buzzing sound that my phone has when it is plugged into a car charger when I am listening to music. I searched for a couple hours, bought 3 different aux cables, and couldn't seem to figure out what the problem was. Then somewhere, not sure where, I read that car cigarette lighters do not have a noise filter in them (whatever that means). The absence of this is causes what is called ground loop noise feedback. In that same post the poster suggested that all you need to do is find a ground loop noise filter to fix the issue. So after I did a quick Google search and Amazon came back with a few different hits. I read the reviews and ultimately decided to purchase a product by the name of "Kensington Noise-Reducing Aux Cable". Below is a picture of the cable.
I was a little nervous at first because I just didn't see how a little box with a chip inside of it could filter out that awful noise without reducing the overall sound quality. To my surprise it worked and the sound quality is just as amazing as it always was!!!!!!! I kid you not when I say that stupid high pitched buzzing sound has been staring as the antagonist in many of my nightmares over recent years. No matter what phone, car, or cable I had, that buzzing noise was always there. Now thanks to this little gem it will forever be a memory of a bad dream.
Google the name of the product to alleviate all of your woes with those charging noises. I promise you won't be disappointed with the results. If you do purchase the product please take a moment and let other members know what you experiences are.
Hopefully this helps you all!!!