similar that's used for outputting ipod/CD player to standalone speakers or car stereos. My bro in law installed a new MP3 player over his car's default stereo console so he can hook up his 20GB mp3 player to the car's mp3 unit via some simple cable to output it to car speakers. The mp3 player of the car had a plug hole to accept these kinds of cables. The cable should be available at RadioShack, while the other.... more work should be avaialbe at places like Circiut city and Best Buy. U'll also need to install it yourself or pay for installation.
I used the same cable to hook into my zire71 headphone jacks and my music was outputted to the car speakeres as well. Nice touch. I may consider doing that if i ever get my own car