Car amplifier and drum subwoofer to how to connect the computer ...

My computer is connected to the car stereo, to a cable one end is plugged into the computer headset plug, the other end if the audio input, to a machine, 12V, the audio cable input, open to AUX input on the good, in the use of the machine to push amplifiers, amplifiers push the speakers and guns, a bit of a hassle, but it's also simple, as long as you have something on the line, of course, 220 to 12 transformer is essential Oh,