Vehicular communications are becoming a reality driven by various applications. Among those applications safe navigation support is of most significance. In designing such navigation safety applications, reliable dissemination of data, i.e., \emph{every affected vehicle} receives data, is the key issue. Past research focused on the reliable dissemination problem of plain media type (e.g., text) safety message whereas we look at the problem of reliable and efficient dissemination of multimedia type (e.g., video, audio) safety information. Considering the potential volume of multimedia traffic and the unpredictability of vehicular networks (e.g., partitions, packet errors), reliable and efficient multimedia dissemination is non-trivial. By using a recently developed technique, \emph{network coding}, we describe an efficient way to achieve reliable dissemination. Simulation results show that in a typical setting, with representative channel errors/losses our approach yields near 100\% delivery ratio as compared to 92\% delivery ratio by traditional multicasting. More importantly, the overhead is reduced by as much as 60\%. If the column of vehicles on the road has gaps, network coding jointly with ``data muling'' on vehicles in the opposite direction can deliver the multimedia files to disconnected components faster than other known schemes.
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