Nice write up, I used to work for Bournemouth car hifi back in the mid 90's installing pheinix gold equipment and Clifford alarms and we had many an argument regarding this subject... We always ran rear speakers in bridged mono along with the subs in low pass bridged mono. For the stereo imigary We then ran a minimum of 2x6" and 2xcomponent tweeters up front normally pod mounted in the tops of the front doors through a crossover network. This was a very simple but commonly used system.. All people ever wanted was bass most of the time lol.. I have in my m3 a direct line audio setup two 10" Orion subs and harmon kardon up front and it sounds amazing.. As for the starlet lol it has a head unit to fill the hole and no speakers as u couldn't hear it if u wanted to lol