ok stupid question number 2 of the day , i want to keep a stock stereo in my car. how do i know whats in there now. whats the diffrence from the plain old stereo , or the bose or the monsoon. it currently has a am/fm/casette player but no rear speakers work. want to find one here or e-bay , had a stock one to try to test it but it didnt work out the way i planned.