—Vehicle-to-vehicle and vehicle-to-infrastructure wireless communications are currently under development to improve traffic efficiency and safety. Routing protocols enabling multi-hop communications represent a major technology for information dissemination within vehicular ad-hoc networks. The high node’s mobility and propagation conditions experienced by vehicle-to-vehicle communications require a careful routing protocol design to ensure its successful operation and performance under realistic environments. To this aim, this paper analyses the impact and importance of adequately considering physical layer effects to correctly quantify a routing protocol’s performance, and understand its networking operation.