Subwoofers in a cruiser mopar

As far as rear speakers all it does is add extra volume. You want to set up the sound stage to come from a bit above the dash or as close to it as possible. Have you ever been to a concert or even the symphony? How much sound comes from behind you? Only the low end frequency that is bouncing off the walls. There are no speakers behind you. Do your ears face forward or backward? So at most you would put woofers in the rear of the vehicle and subwoofers in the trunk. As far as amp power yes get the rms power that is as close to possible of the subwoofer. If it is to much bass for you turn the gain down. Power is not what kills speakers, it is the distortion. When an audio signal starts to distort it changes from a sign wave to a square wave, which is equivalent to tapping the speaker with a battery.