If that pointed front is going to be structural, meaning that if it split apart at that point it would cause problems with the fairing, then you will want to put a metal strip over the pointy arch end, either inside the arch or outside (outside would give more resistance to splitting).
Otherwise in my experiences with plastics, the spirally sway that will happen as you ride (which you may not even notice) will eventually split that point, and the two pieces will spring apart.
If the arch was passing loads back and forth that without it cause greater sway, vibration, or whatever in the coroplast
fairing, it may begin to break other parts of the supports, over time. Since it's inside, you probably won't notice it, either, till something gives way during a shock load sometime (big bump or pothole, probably).
The metal strip should be bolted or riveted thru the arch at at least two points along it's length on each side, so it can't swing out of position like a knight's helmet visor going up and down.
It can be just 2-3 inches long on each side, with a rivet or bolt a very short way from each end of the strip, and another an inch or two forward of that one.
Other than that, I'm intrigued by what shape this may end up with.