panasonic cq dpx33

I am installing this deck into my car and it has been a while since I have done this kind of thing. My question is of the wires that come out of the deck I have the speaker wires labled,the red for power and the blue for constant(i think that's what you call it) but i have two yellow wires and two black. I realize one black should be for ground but what is the other and what are the two yellow ones? Please help. Ynnad

Both blacks go to ground and both yellow go to +12v constant, red wire goes to +12v ignition, blue wire is for the power antenna or amplifier trigger and gives a +12v output.Top Secret, I can tell you but then my wife will kill me.

thanks