Through a soma design process, we explored how to design a shape-changing car seat as a point of interaction between the car and the driver. We developed a low-fdelity prototyping tool to support this design work and describe our experiences of using this tool in a workshop with a car manufacturer. We share the co-designed patterns that we developed: re-engaging in driving; dis-engaging from driving; saying farewell; and being held while turning. Our analysis contributes design knowledge on how we should design for a car seat to ‘touch’ larger, potentially heavier parts of the body including the back, shoulders, hips, and bottom. The non-habitual experience of shape-changing elements in the driver seat helped pinpoint the link between somatic experience and intelligent rational behaviour in driving tasks. Relevant meaning-making processes arose when the two were aligned, improving on the holistic coming together of driver, car, and the road travelled.