I wouldnt reccomend audiobahn. In fact i just saw a brand new one that was all hooked up right go up in smoke. Must say made a nice smoke show on its way out. More show than go. Anyways im a firm believer that any really system is going to need an amp for atleast the front speakers. Your head unit may say 45x4 but i bet your only getting maybe 20 or so. I would look at a 4 channel for the front speakers and bridge the back to a single sub. You can run the rears off the deck.