This paper presents a X-in-the-loop (where X: Model, Software, Hardware, Driver/Human, etc.) driving simulation platform, developed at Siemens PLM Software, that facilitates the design, development, testing and validation of Advanced Driver Assistance System (ADAS). The paper outlines the essential components of the simulator and demonstrates the usefulness by two autonomous driving functionalities i.e. adaptive cruise control and autonomous intersection crossing. In addition, the paper highlights the key features of the platform.