This paper discusses the potential role of emotion in changing our machine design, based upon the experiments conducted for about 20 years by TMIT (Tokyo Metropolitan Institute of Technology) research group headed by the author. An automobile design shares the same issues as those in our future machine design. In order to clarify these points, experiment to detect driver’s emotion were carried out. Our research to detect driver’s emotion started from the observations of a driver in driving, and based on them, experiments to detect driver’s emotion from face, sound and body were carried out. The following points were made clear. (1) a driving simulator is not good because a subject is in a different state of mind and physical conditions from actual driving. (2) Dynamic image processing is valid, but to make it effective, a simple image processing technique must be developed and a technique to remove lighting change effects must be developed. (3) When detecting from face, feature points must be carefully chosen. (4) Although sound is very promising, drivers do not utter voices often and if they do, their durations are very short. But if we introduce voice guidance systems, which would be much easier in EVs, detection from sound would work far more effectively than that from dynamic image, because images are very difficult to process due to the frequently changing lighting. (5) Physical movements can be used very effectively to detect fatigue. (6) Physical movement may be utilized for safer driving. If a new communication system between a driver and a car can be developed, the design of a car would change drastically. We do not have to, for example, use a wheel to steer. We could use bars. Equipments can be placed far away from the driver, if voice guidance systems can be introduced. Thus, a far greater degree of design flexibility could be introduced and a driver and a car could work better together as a team.