2 Dawg

....my goal is to achieve a simple, efficient and value oriented solution to the underwhelming Sony System in my new FX4 with Sony & Sync (no nav). I am not a car audio tech and have zero experience/knowledge in the field...hoping someone could answer a question. Reading the reviews on the Alpine KTP-445 Power Pack product, this sounds exactly like the kind of boost I need to satisfy my needs without the complications involved with tearing down the truck by adding a 4 channel amp with all of the wiring, harnesses, etc. I am replacing all door speakers in my truck with MM Polk Audio. My Question - is it possible to run the front components (6.5 in doors and tweeters in pillars) off of the Alpine Power Pack and utilize the power from the factory head unit to run the rear door coax speakers? Just curious if there is a way to salvage the existing HU power from the factory system in conjunction. I have read from several on this site that the rear door speakers should be the last priority so I'm trying to place an emphasis on the front components with regards to both quality of speakers and power supply. Thanks in advance for any input, expertise and suggestions!