MPS-CAN analyzer is a research tool that supports the Response Time Analysis (RTA) for Controller Area Network (CAN). It takes into account various queueing policies; buffer limitations in the CAN controllers; and mixed transmission patterns supported by the higher-level protocols. In this paper, we extend the MPS-CAN analyzer to support RTA of heterogeneous automotive networks. Within this context, first we implement RTA for Ethernet Audio/Video Bridging (AVB) messages in a single-switch architecture. We then integrate the analyses for CAN and Ethernet AVB by exploiting the analysis for CAN to Ethernet AVB gateway. With this integration, the MPS-CAN analyzer supports the analysis for heterogeneous messages that traverse through heterogeneous networks consisting of CAN and Ethernet AVB. We also evaluate the newly implemented analyses by conducting an automotive-application case study.