I live on a gravel road and have to drive through some gravel on the roads occasionally. Especially when there is some moisture on the ground (often in the NW), I hear a lot of rocks coming off the front tire hitting my radiator. Even though there is kind of a wimpy screen covering the cooling fins, the bottom radiator tank, and some modules and their plugs, are exposed.
The bottom module has a guard, but both the module plugs are completely exposed:
The rocks that hit are chipping away at the paint, but I don't see them piercing the radiator tank, or breaking the plugs, but over time they could do some damage. But, the sticks, branches, and occasional "objects" on the road that live in the center of the road that you don't see in time to avoid, could leave you stranded.
I thought about a mud flap or fender extender, like the one I had on my Concours, but nobody makes one, and I frankly thought it wouldn't look very good. So, instead I made a guard out of 16 gauge steel screen, and mounted it with the bolts that hold the bottom of radiator and the modules. I used longer bolts and added stand-offs to hold the screen away from the radiator.
The guard doesn't show at all, and the total cost of this project was $20.