Anyone own a WRX or know anybody who does? They got venting, right? What did they do right to prevent bad weather from messing up the engine bay? Anybody designing a Carbon Hood with vents and ducting? If they did, they'd get a whole bunch of buyers I bet!
I don't think it would mess up the engine bay at all. Water wouldn't hurt anything. Would help cool everything down if anything. As long as it doesn't get on the exhaust manifold. I'm sure the scoop would direct everything over the intercooler like the stock ducting does or it would loose a lot of efficiency.