In recent years the development of automotive embedded devices has changed from an electrical and mechanical engineering discipline to a combination of software and electrical/mechanical engineering. The effects of this change on development processes, methods, and tools as well as on required engineering skills were very significant and are still ongoing today.At present there is a new trend in the automotive industry towards model-based development. Software components are no longer handwritten in C or Assembler code but modeled with MATLAB/Simulink™, Statemate, or similar tools. However, quality assurance of model-based developments, especially testing, is still poorly supported. Many development projects require creation of expensive proprietary testing solutions.In this paper we discuss the characteristics of automotive model-based development processes, the consequences for test development and the need to reconsider testing procedures in practice. Furthermore, we introduce the test tool “TPT” which masters the complexity of model-based testing in the automotive domain. To illustrate this statement we present a small automotive case study. TPT is based on graphical test models that are not only easy to understand but also powerful enough to express very complex, fully automated closed loop tests in real-time. TPT has been initially developed by Daimler Software Technology Research. It is already in use in many production-vehicle development projects at car manufacturers and suppliers.