The aim of this master thesis is to “provide a deeper understanding of the (dis)comfort experience of side supports in an automotive seat.” The goal is to provide recommendations for design and eventually a (re)design of comfortable side supports in car seats. With the future prospect of an autonomous, shared and electric driving experience, side supports might obtain new purposes supporting the passenger. There is a need of objectifying the (dis)comfort of side supports in current and in future car seats to gain insight into relationships to human anthropometry, performed activities and the design of seats. A literature review 2 presents an alteration on the comfort models of Vink & Hallbeck (2012) and Naddeo (2014), aimed at improvement of the physical seat and components. All relevant objective comfort measurements and parameters and variables of the seat and passenger are structured, explained and their optimal (dis)comfort values are described. Scientifical evidence relating side supports to (dis)comfort is marginal and should therefore be studied. The effect of changing the variables of a side support (height, foam hardness, contour and cover friction) are studied in their relation to (dis)comfort. Both static and dynamic (dis)comfort is evaluated, alongside pressure recordings and characterization, looking for the optimal design of a car seat bolster and backrest wing. A redesign of a BMW 5 Series seat, lowers the bolsters from 55mm to 40mm, decreasing discomfort while relatively maintaining a high proportion of its (dynamic) comfort. The backrest wings is fitted with a soft (2kPa) cut foam with 15mm thickness at the side, gradually becoming thinner to the main surface. This preserves low discomfort in widest adjustment and increases dynamic comfort in narrow setting. Internal evaluation in a realistic and long-term driving environment proved its successfully improved comfort. Future autonomous driving, its concept interiors and use cases; intelligent entrance, transition, boost, life experience and holistic health; are analysed, looking into technological developments and consequences for the interior and use of a car. Various secondary activities; relaxing, sleeping, laptop and device work, social interaction and in/egress; are identified and analysed, confining the required space and optimal posture for the design of a conceptual future autonomous car seat. A new 6D adjustable seating concept is developed. The seat has an alteration on the current adjustment system, adding a lateral rail for sideways movement, a planetary gear for normal axis rotation and an individually controlled 4-beam mechanism, enabling the roll rotation alongside height adjustment. The seat requires medium-firm upholstery, supporting the body and distributing pressure at the buttocks and shoulder areas. The cushion is 100mm high, made of a latex rubber. Airbag size should be larger in reclined positions and smaller in upright positions to increase safety.