I'm looking for a cable that does RCA audio out (white and red wire) with USB for charging that'll connect to the iPhone dock. I want to hook up my iPhone to my car stereo using only one cable to charge and audio out. The composite and component cables apple sells won't work, I tried and for audio they work fine but if I try to watch any video it doesn't show up on my iPhone because it thinks it's hooked up to a tv. Right now I have it hooked up through the headphone jack for sound and a USB to charge, but would like to have only one cable instead of having two cables, one coming out of each side of the phone. Thanks for your help.