[ijames]

Hmm, your plan is to vent up towards the front of the hood, right? That means when you say "get some forward motion and the water will be ejected", doesn't that mean it will all land on the windshield? I think you should put a couple of hose barb fittings in the lowest corners, and then underneath attach short pieces of tubing that extend down to level with the bottom of the frame so the water goes down under the car. Something like 1/4" ID tubing won't pass enough air to disrupt your airflow, I wouldn't think. You could also put window screen over the outlet to stop debris from entering, and if it snowed the snow should build up on the screen mesh instead of going through and filling the duct. Yes, it restricts the airflow but it keeps stuff out.