In recent years, distributed ledger technologies (DLTs) and blockchain have become disruptive technologies to support distributed and trusted sharing ecosystems in various domains. Among the potential scenarios that can leverage their benefits, cooperative intelligent transport systems (C-ITS) and autonomous vehicles (AV) represent a key trend of the next digital era to build a safer society. However, different aspects such as performance and practical issues, as well as conformance with current standards and legislation, may hinder the adoption of DLT in such scenarios. This article analyses the potential applications that could leverage DLTs features and the challenges to be overcome in the coming years to foster the adoption of DLTs in C-ITS and AV. Through this analysis, we additionally provide a set of potential research directions and ways forward to exploit the advantages of DLTs in C-ITS and AV in terms of decentralized trust and transparency.