In the realm of 5G-enabled Intelligent Transportation networks, despite persistent unresolved challenges exploration of new technological paradigms is underway. Regardless of the new explorations in Vehicular communications, dynamic nature of vehicle networks and rapidly fluctuating channel conditions make it grim to achieve comprehensive recompenses. Many researchers had focused on mitigating the effects of fading channels, interference and throughput under dynamic channel conditions. Very less attention was made to address continuous time varying channels and its implications over the channel sate information. This work proposes a novel approach employing two-way half-duplex decode-and-forward relaying with Non-orthogonal multiple access to counteract the impact of outdated channel state information and imperfect successive interference cancellation resulting from dynamic channel behaviour. This is achieved through the utilization of Self-proclaiming relay selection and multi-phase transmission strategies. Explicit closed-form equations are developed and sum outage probabilities are analysed based on the location of decodable relay nodes between the source and destination vehicles. The performance of the proposed strategy is compared with two-way amplify-and-forward relaying and two-way decode and forward relaying with and without network coding. Furthermore, an analysis of the effect on Packet error rate is conducted across various sub transmission phases, while also examining the trade-offs associated with determining the optimal phase value during the data transmission phase and relay selection phase.