Owing to the increasing number of requests from smart devices to mobile edge computing servers, unmanned aerial vehicles (UAVs) have emerged as alternatives for providing computing resources to these devices. However, satisfying the delay requirements for all smart-device requests is challenging because UAVs have limited computing resources. To address this problem, we propose a vehicle-aided task offloading scheme for UAVs. We designed a Stackelberg game model to determine the optimal UAV demand and vehicle resource prices. Simulation results show that the proposed scheme completes the requested tasks faster than other benchmark methods.