Aux input engine noise
 

I've been trying to research this issue with little result for BMWs. On my '08 X5 I use the aux input for my iPhone with power coming from the inside armrest cigarette lighter via a usb power plug. The iPhone is using a line out cable that splits the audio to a standard headphone plug and the power is coming from the usb end. I get a lot of engine whine/noise that can be pretty annoying when listening to softer music, especially when at higher speeds on the highway. I haven't found much info specifically for the X5, but other brands have had similar issues. Is the only answer something like an in-line noise suppressor?

usb power plug:
http://www.amazon.com/gp/product/B00...ls_o00_s00_i00

noise suppressor:
Amazon.com: Pyramid NS12 12 Amp InLine Noise Suppressor: Count Bishops: DependableResource

Any input or advice would be greatly appreciated.

Seriously? Nothin'?

Dunno about the ones you listed, but this item from eBay worked for me. Though I'm not using it on my X5, but on my other car.

iPod Zune iRiver MP3 Hum Noise Filter Eliminator NEW | eBay