We tackle the challenges of accurately replicating modern automotive network architectures, particularly those reliant on automotive Ethernet and Time-Sensitive Networking (TSN), in simulation environments. We describe an open-source TSN simulation model tailored to match a real-world TSN testbed built using off-the-shelf hardware. We address key challenges such as hardware and software imperfections as well as varying data traffic patterns from automotive sensors. By incorporating real data traces from LIDAR and camera sensors, we improve simulation accuracy. Our findings underscore the importance of accounting for hardware and software nuances to ensure faithful simulation results, thus advancing the reliability of automotive network simulations.