One of the next challenges in vehicular technology field is to improve drastically the road safety. Current developments are focusing on both vehicle platform and diverse assistance systems. This book presents a new engineering approach based on lean vehicle architecture ready for the drive-by-wire technology. Based on a cognitive functionality split, execution and command levels are detailed. The execution level centralized over the stability control performs the motion vector coming from the command level. At this level the driver generates a motion vector which is continuously monitored by a virtual co-pilot. The integration of assistance systems in a safety relevant multi-agent system is presented here to