We propose the use of projection mapping as a prototyping tool to create an experimentation environment to design, evaluate, and control immersion experience in future autonomous vehicles. As the first step, we conducted expert interviews with professionals in the automotive industry to understand the general implications of prototyping tools in future mobility solution development and their usefulness in concept test settings. The interview results reveal that projection mapping is one popular prototyping method for automotive professionals to demonstrate immersive future user scenarios. The paper includes additional insights from the interviews and current work-in-progress.@en