After driving for hours in heavy rain, I've opened my hood to check out my CAI. The first foot of pipe after the filter was wet and dirty....so to answer your question.....water could be "splashing" on to the filter all the time and nothing will happen.

Think of it logically....it's much easier to suck air through a straw than water....so as long as the whole filter isn't submerged only air should make it all the way up the pipe. :thumbup: