Simulation of real time situations is a time tested software validation methodology in the automotive industry and array of simulation technologies have been in use for decades and is widely accepted and been part & parcel of software development cycle. While software that is being developed needs detailed plan, architecture and detailed design, it also matters during its development that, it is built in the right way from the very beginning and is fine tuned constantly. Especially for Software-In-Loop simulation (SIL), plenty of practices/tools/techniques/data are being used for simulation of system/software behavior. When it comes to choosing the right simulation technique and tools to be adopted, often there are discussions revolve around cost, feasibility, effectiveness, man-power, scalability, reusability etc. As automotive software validation is data driven, we deal with myriad of ground truth data for simulations, ranging from vehicle dynamics to vehicle models to environment factors (road, test track, weather). While infusing the ground truth data (physical data) in a simulation environment is still possible, availability of the same is often sparse, owing to test track constraints, availability of target objects, high risk maneuvers (involving higher vehicle speeds, narrow road curvatures, weather factors, accident reconstruction etc.) To tide over these constraints, in recent times, organization are inclined towards adopting virtual software simulation techniques, as it offers precision, scalability, cost and time effectiveness, and helps developers with early feedback to fine tune the software. CarMaker (Third Party Simulation tool) covers all the benefits stated above when it is integrated with the software (to be tested) in a closed loop. Vehicle data, Sensor data and real time scenarios (use cases) can be readily modelled for customer requirements for a product/SW and simulated and tested readily to provide to the developers on system/SW performance, ranging from ego dynamics, trajectory, camera/radar calibration, component/subsystem performance, accident severity, accident implications dealing with costs & damages, impact velocity, collision mitigation etc. Closed loop simulations are widely in use during development and testing of safety/cruising applications like ACC (Adaptive Cruise Control), EBA (Emergency Braking Assist), LCF (Lateral Control Functions) and also assists in functional areas of NCAP (New Car Assessment Programme) [1] and GIDAS (German In-Depth Accident Study) topics.