I am hoping that some audiophile out there can help me solve my dilemma. I have a 1981 320i and I am in desperate need of a new sound system for the car. I want to replace all the factory sound equipment and replace it with a really nice system. My question is what size speakers can I put in the vehicle and what kind of CD receiver can I put at a 90 degree angle relative to the pavement and still get jog-free CD sound out of?