One Stupid Question

The water will wash over the intercooler, then come out the underside of the car - the scoop is not the air intake - its purpose it to provide air flow to the top mount air-to-air intercooler on the top of the engine (there is no way for it to get into the engine through the hood scoop)

It cools your intercooler even more, giving you more horsepower! The STI even has a system to spray water into the IC. I tlooks like windshield washer nozzles and they are mounted right in the scoop.

It may help to cool a little bit, but won't quite do the cooling that the spray will do. You lose the heat when the water evaporates, which the misting spray will do on contact. The heavy rain will definetly do something, but it won't evaporate quickly at all (especially in the constant rain...too much water!). In real-world conditions, it probably won't make that much difference, would it?