^great question. it comes with underside hood baffles that nearly cover up the "holes" in the hood... although still functional (venting) there's just a small area where the water actually falls down. (or channeled) I immediately took those baffles off... since my car is never in the rain.
second, the hood is soo new, i haven't washed the car yet... so i'll be curious as to what gets wet after wash