On our trip in 08, we had the Roadmaster Guardian on the front of our toad. While it kept pebbles and such from hitting the front of the toad, it did nothing for the pebbles hitting the side of the toad or on top of it. When we got home, I counted over 75 very small chips out of the paint on the hood, top, toneau cover and the driver's side.
We did take the advice of others when on gravel roads and with a vehicle coming towards us, we would slow way down and move as far right as we could. Mostly to no avail as those vehicles coming towards us, did not...especially the large trucks.
We actually saw toads that the people had wrapped in cardboard. Quite a sight.
Ron