Do they all have factory amps?

I have the 6 disc changer dvd player in my 2007 German spec. Nitro. I was wondering if this system comes with a factory amp or not? I have my sub box done and will be purchasing my 4 ch. and mono amp for the system soon. I will run hi/lo converters to be able to use the amps. I have had the radio out, and it only has one plug plus the antenna plug. I have all the speaker wire colors from a link on this site to tap into, but if it has a factory amp somewhere it may be better to tap into the speaker wires there. Can anyone tell me if all the Nitro models have a factory amp or not? Or do I have to pull the rear panel?