This paper proposes new MAC layer based back-off and retransmission strategies for throughput enhancement, in broadcast transmissions of inter vehicular communication. We present adaptive back off strategy which is based on the concept that there exists an optimum contention window (CW) period in a broadcast CSMA/CA system, given the fixed number of users. We also propose a simple probabilistic approach for retransmission which is based on analyzing the local information. Simulation results shows the improvement in the throughput using adaptive back-off and probabilistic retransmission strategies compared to fixed back-off strategy.