I posted about this on the Hondagrom.net forums, so below is my post in a thread discussing some aftermarket front fender options:

Did some things.

Took a closer look at the diving board, I realized it has two parts: the diving board and this small back half behind the fork.

So I made one myself for $free.99

Masked off and cut my stock fender since I wasn’t using it, sanded it, and reattached. The only trouble was now that the fender is cut, it only attaches with one bolt on each end, and the bolt is through a rubber grommet so no matter how much you tighten the bolt, it could still move enough to touch the wheel. I’m not sure how the ADV fender gets away with that because it connects to the same mounting point…

I scavenged some small machine screws and drilled a second hole through the fender and the mounting point to keep it from moving. After a 25 mile ride over potholes and speedbumps it holds up well! Seems like it would be enough for those of you with oil coolers to protect it, didn’t have any puddle I could ride through but I suspect it’ll still throw water up to the headlight, but better than it was before.