sound system question

i was just wondering what size speaker was in the back seats, and what was in the doors. i think there 6x9 in the back and 51/4 in the door. and there are 4 wires going to the speaker, what color wire do i use to hook the new speakers up....thanks

The 4 wires are run in case the vehicle is equipped with the Infinity Sound System, the system is really speakers with amplifiers built into the speaker and a head unit with an "Infinity" label, the factory will run the 4 wires even if not so equipped with the Infinity Speakers/ Head unit, they just do not include the Relay system to turn the power on with the Radio when the vehicle is not equipped. The outside connections are the hot and ground for the Amplifier and the center connections are the actual speaker leads from the Radio. I can't tell you which wire is which but that should not be too much of a problem to figure out if you have a continuity tester or ohm meter to test the polarity of the wiring between the Radio and the Speaker connector. It may also be possible that a Car Stereo shop may have a harness that plugs in with just the speaker wires coming out of it and not the power leads so you can hook up aftermarket speakers.