Water is interesting in that light reflects off it but also diffuses into it, softening colors and shadows. So, shadows get cut a little bit and softened up from light bouncing around and brightening things up. The speculars on the top reflecting get cut some, but not completely blocked by shadows. However, there's an ambient occlusion darkening that also happens under vehicles, and that does block more reflective specular. So, you see the specular diminish as it goes further under the car. Original FUEL code didn't apply vehicle AO to water. So, I had to add that in then tweak it.
Water is interesting in that light reflects off it but also diffuses into it, softening colors and shadows. So, shadows get cut a little bit and softened up from light bouncing around and brightening things up. The speculars on the top reflecting get cut some, but not completely blocked by shadows. However, there's an ambient occlusion darkening that also happens under vehicles, and that does block more reflective specular. So, you see the specular diminish as it goes further under the car. Original FUEL code didn't apply vehicle AO to water. So, I had to add that in then tweak it.