i'm gonna be installing the new alpine x305s stereo head unit. well in the ordering process from crutchfield, it asks if i want the wire harness to bypass the factory amp or the wire harness to integrate it. i really don't know which is the best decision to get better sound out of the stereo system. i've already replaced my antenna and installed 4 new infinity speakers, so i want to get the most for my money. any suggestions?