Cord That Connects Ipod To Dvd Player How To Connect Ipod To Vehicle Through DVD Or Headphone Jack?

How to connect Ipod to vehicle through DVD or Headphone Jack? - cord that connects ipod to dvd player

Is it possible to connect an iPod with a cable through the DVD player or a helmet in the car? If so, how? I have a cable that can connect to the messenger, but not sure if or how I can do. Please help! :)