Future mobility development is user-centric, integrating user feedback into the early phase of development is essential. The Mixed Reality Tool is a novel approach to automotive interior visualization and evaluation using green screens and mixed reality glasses. Utilizing a four-sided green screen arrangement in a studio setup, realistic automotive interiors are visualized, allowing for various evaluations and user interactions by immersing the real individuals into a virtual environment. Two examples are explored: (1) Showcasing the interior of a shared automated vehicle (SAV) and overlaying a real person using Chroma keying. (2) Simulating an automated car interior to analyze the possible transitions and time involved in various Non-Driving Related Activities (NDRA) carried out by real individuals. This innovative approach offers numerous advantages over traditional VR glasses, including improved immersion, realistic integration of real elements, and the ability to conduct evaluations with human presence for enhanced user experience and design optimization.