The poweramp is integrated in the Audio 20. And yes, there are wires from the back of the Audio 20 to the small speakers behind the seats. But the audioinput on these wires is meant for a speaker not for the input of a separate amplifier. You wille have to attenuate this signal some way or the other before feeding it to an other amp or you willl get very distorted audio. Also I think there is not much room for bigger speakers behind the seats. If you want to intercept them for input to another amp bets place is behind the Audio 20 I guess. More info here
But if you have little knowledge about the subject best would be to go to a specialized audioshop. But you can always give it a try ofcourse.
But if you have little knowledge about the subject best would be to go to a specialized audioshop. But you can always give it a try ofcourse.