Split metal fenders up front might be practical although it might be a custom fabrication job. If there's any damage to the front from the bus' restraining bar or wind it wouldn't be necessary to replace the entire fender.

I'm considering a downtube splash guard instead of a front fender since I occasionally use the bus rack and the restraining bar would break a plastic fender. But I'm leaning toward a plastic fender for the rear since I occasionally ride off-road and am a little concerned about sticks or debris jamming. My rear rack already blocks quite a bit of splatter but needs a little help near the saddle.