The proportion of older people in the population is rising, as is the proportion of older driving licence holders. The needs and abilities of older drivers therefore need to be considered in vehicle design. Our research is focussing on the multidisciplinary identification of design requirements for aged drivers. Research on older drivers has become a field of interest in various research domains and technical areas but coherent results are still missing. We need interdisciplinary approaches directly aimed at supporting older road users. We suggest a functional analysis in order to assist us in identifying the actors, aims and limits of our system. Our analysis is motivated by the need to contrast diverse perspectives to obtain new knowledge and research directions. The functional analysis allows us to make statements about the knowledge needed by designers and the interrelation of actors and factors according to system. It also helps us to formulate further research recommendations for car design requirements for older drivers.