Autonomous vehicles provide a unique challenge for simulation to effectively and performantly model due to their system level complexity and the inclusion of autonomy software. This environment is made even more challenging when looking at the interactions of humans in-the-loop with the vehicles and autonomy software and also how to include more simulation in the testing process for Autonomous Vehicles. With the use of a software framework built from a Commercial off the Shelf (COTS) game engine the Ground Vehicle Systems Laboratory demonstrated the feasibility of real-time human, software and hardware in the loop testing of autonomous systems. This approach facilitated the execution of two major events which are described herein.