He would not be violating any regulations in this case. He's not in a restricted flight area, is not operating the UAV from a vehicle and he is not flying directly over a vehicle. That's it.
Actually he said that he would be directly over the vehicle, so 107.39 does apply. It's not a stationary vehicle, so 107.39 (b) is not met, but if the driver of the vehicle is part of the operation then 107.39 (a) could be argued to be met.