We present an event-triggered based OFDMA resource allocation algorithm in conjunction with the solution to a distributed optimization problem. The optimal OFDMA subcarriers assignment is supported by the sensitivity function of the objective function to exchange information between the nodes of the underlying network. The resulting sensitivity-based event-triggered policy invokes a cross-layer communication protocol by introducing sensitivity-dependent weights in the resource sharing optimization problem at the MAC layer. For practical evaluation purposes, we consider steering of wireless multi-vehicles, where each vehicle on its own is controlled by a cluster of collaborative on-board distributed processors communicating over a single wireless link.