wait wait wait... what? are u sure all the speaker's power supply give 12 volts? what if its giving out 4? or 6?
@959
sir as you can see the speakers that he mentioned do not have a built-in amp rather the amp is in the sub unit. These speakers for example do have built in amp.
http://www.keystodriving.com/images/pc_speakers.jpg
anyways in ur case all u have to is that just connect the wires of the speakers to the speaker out wires from your head unit. u cant and should not use the amp thingy with the speakers as the amp of the head unit will be sufficient to run these speakers on its own. if the speakers wires have connector at the end then you will either have to cut the connectors off or make a female connector with wires on one side.
having said that, the sound might not be like how u experience in ur room.
by the way see how the speakers look mounted on the A pillars in front and back...