Inside highly mobile vehicles, In-Vehicle Networks (IVNs) are designed to meet the requirements of reliable and deterministic communication. When two vehicles communicate, however, decentralized best-effort wireless connections threaten to re-introduce the problems that IVNs were designed to solve. Moving to centralized coordination cannot meet the requirements of Vehicle to Everything (V2X) systems for a wealth of reasons from capacity bounds to privacy and safety. In this paper, we thus propose hierarchical cooperative Time Sensitive Networking (TSN) as an approach for cooperating (rather than centrally managed) TSN networks via best-effort wireless links. Our approach is both suited to mixed IVN and V2X systems of highly mobile nodes like platooning and generalizable to similar systems requiring streams across cooperating TSN networks. We also present an approach for the simulative performance evaluation of such systems and describe an Open Source reference implementation using well-established simulation tools. We conclude with the results of a proof of concept evaluation to demonstrate the feasibility and dynamic adaptivity of our approach.