how should i connect my dash speakers

In my 06 trailblazer there are 4 door speakers and a pair in the dash. The unit im installing is a panasonic cq-vw100u it has 4 rca preamp outputs (front/rear) and one preamp sub output. im already using the 4 channels for the 4 door speakers and the sub output for the sub. But the unit also has 4 channels (front/rear) coming out of the power connector at 18 watt rms. What im wondering is if the 4 channels that are coming out of the power connector are correlated at all with the 4 preamp rca outputs for the door speakers. Is it possible to use one pair of channels from the power connector and all four of the preamp speaker outputs, or will i have do divide up channels from the amp to run all six speakers?  

The speakers in the dash are they tweeters? cause if so then you dont need a seperate unit to power them they're usually connected to the front door speakers through a crossover  

good idea is to just leave those unplugged because normally they don't provide much sound anyways and if you still want more sound just put in a compnent system in the front of add individual tweeters power accoustic makes good tweeters with built in crossovers so u can just hook them up as speakers!!