In the hood hinge pockets at the rear the wheel well rolls over and meets the firewall. There is a crease, or maybe two I don't remember, in the wheel well metal that allow water to run out of that area onto the ground.

Then there is an opening in the metal that is vertical between the hinge pocket and the underhood area. It will always be clear, but if the previously described drains are NOT, water will drain through this one to an area under the master cylinder and the battery on the other side.

Hope this helps,