If you go to my website..
http://1phagt.innernot.com amd take a look at some of the pics of the car, look at the Erebuni bumper I have. I have the PRI set up cold and the filet sits in the open with only the grille pretecting it. I have had it this way for two years and living in Florida where it rains cows and bulls at times, I have never (knock on wood) had so much as a hiccup driving through torrential rains. Don't get me wrong, I don't suggest driving through standing water and submerging the filter sucking it all in and vapor-locking, but I don't think a little water will hurt either.
-Henry