More than 23% of annual vehicle accidents are rear-end collisions, this gives an important test-case for enhanced collision avoidance approaches based on v2v wireless communications. V2V wireless network concern with the impact of a IEEE 802.11 based multi-hop MAC protocol that propagates an emergency warning message (EWM) down a platoon of cars on a highway. The design objective is to ensure reception of this message with stringent delay constraints so as to provide drivers with requisite available manoeuvre time (AMT) to avoid rear-end collision. This V2V wireless communication protocol provides a realistic simulation in Ns-2 for various topologies (lane-1& lane-3) and the performances were evaluated for different parameters such as EWM delay, delay due to overhead packets and probability of successful delivery of the emergency warning message (EWM). © 2009 IEEE.