Mechatronic systems integrate mechanical, electrical and software subsystems. They are increasingly important in mission-critical infrastructures in different domains including automotive, healthcare, energy and transportation sectors. As such, the adequate testing and validation of such infrastructures are of prime importance. Mechatronic systems testing has been supported by different isolated industrial and research approaches including automated test infrastructures, model-based testing, and test execution engines. While these approaches have individual benefits, they are usually applied in isolation, suffering from different weaknesses. This paper reports on an integrated model-driven approach for mechatronic systems testing, where existing approaches are combined and enhanced. The result is unprecedented levels of automation and testability. We discuss the design and implementation of our approach, illustrating its use with a hybrid calculator example.