The current and future greatness challenge for the car and light truck manufacturer is to develop less costly, weight efficient vehicles within shorter lead times. Based upon these circumstances, the technique of “systems design”, “systems integration” and “total interior systems integration” will be discussed in detail. Component integration and systems integration has been taking place in automotive interior design for sometime. However, total systems integration is relatively new. A potential area for interior systems integration application is in side impact “upgrade”. For added side impact protection the door structure and impact beam can be upgraded, a side air bag utilized, door/sill interlock, crushable arm rest, etc. Individually, each of these systems could meet the new side impact requirements; however, at a cost, weight and quality penalty. Utilizing two or more of these systems in combination could lead to an optimum solution (total systems integration). Other systems related to the body interior that can be designed by total systems integration are seats and I/P's.In addition to the interior system integration examples presented, a discussion will be presented regarding a new CAD design and CAM processing method called “morphing” which can enhance the optimization of systems integration.