the power that comes out of your ipod is made to power speakers that are headphone sized. were talking millimeters...your car has 4 or 6 speakers that are inches in diameter. so you can plug your ipod into your car speakers but you will need to amplify the ipods output. if you get a 4channel amp to power the speakers you can go straight to the amp with the ipod via cord with headphone jack on one side(ipod) and rca on the other side(amp)