Nowadays, the amount of software in modern cars as well as its complexity increases rapidly due to applications such as autonomous driving. Consequently, more powerful computing platforms are employed and software applications are developed in a distributed manner, e.g., by applying the widely established microservice pattern. Microservices introduce additional complexity regarding the communication between the individual services. Solutions that address these challenges have been developed. One of these solutions that is specifically designed for an application to the automotive domain is the CARISMA approach. The main idea of CARISMA is to employ a service mesh architecture that is adapted to the design of future electric/electronic (E/E) architectures. In this paper, we present an approach to describing a topology of services deployed based on CARISMA including their relationships regarding service-to-service-communication using the Topology and Orchestration Specification for Cloud Applications (TOSCA). This way, a complex CARISMA topology can be described using a model-based approach relying on abstract and reusable components. This increases the understandability of the modeled topology and enables an automated deployment and management. Furthermore, because only desired service-to-service communication paths are established, the complexity of the resulting CARISMA configuration is reduced.