2004 Soundmark radio

[TC33]

I recently acquired a 2004 TC Ultimate with the Sound Mark radio. At the ack of them radio, there are 3 plug in connectors present. But, I do not have a CD changer. Does my car come with the changer wiring installed, and a subwoofer? Where would these be located? I looked behind the fuel door on the left and behind the spare and found nothing. I did find an empty plastic tubing on the left side, but no mounting for changer can be found.