If you are looking to connect like a ipod or something of that nature amp,dvd player. You need to take out your deck out of the dash, then on the back you will see a left and right in (red&white) plug Your Rca's In To Them It is That Easy ! !
For an amp You Need RCA To RCA Cable ! !
For an Ipod Or Mp3 Player You Need a RCA To 3.5mm ! !
Also If It Is for An I-pod Watch Out when Turning up the volume as it can be very loud and blow your speakers