Car infotainment systems feature an increasing number of functions to keep pace with consumer needs. The GENIVI Alliance aims to facilitate this evolution of infotainment systems by developing a common baseline where services of different suppliers can easily be integrated on a single hardware platform. Since the huge number of services creates more dependencies and interactions, more effort is required to ensure the same level of quality. We present a novel approach and effective tooling to reduce the effort for the interface verification of in-vehicle software components. Our models create different views of the system. Consistency checks and automated transformations between the views reduce the modeling effort and ensure compatible interactions of distributed software components. Layered reference models separate the description of the structure and the behavior of the services' communication. This simplifies the behavior descriptions and facilitates the usage of different communication technologies, e.g., D-Bus or CAN. Since the reference models are executable specifications, they can be used to verify the communication of the modeled services. This can be tested live or from a trace. In case of required changes to an interface, regression testing can be performed automatically using only the model. We evaluate the benefits and implications of our approach and tool with a case study of an in-vehicle audio function.