Rain has never been friendly to vehicles on the road. Not only does rain make you late to work, but it can cause the road to be more hazardous. Our street systems were built in the 20th century with no idea that flooding might be an issue. The street drains are only made for a few inches of rain. However, during constant rain, our drainage system will be unable to handle the amount of water flow and flooding on street corners will occur. This said, the large puddles of water are not only unfriendly - but a nemesis for cold air intakes.
Cold air intakes use an induction system that retrieves air from the lower part of the car; mainly near the front bumper. Having the cold air intake that low to the ground will create risk of having the water be sucked up from puddles and moved to intake manifolds. This straw like concept has unfortunately happened to many people. Once the water gets to that point in the engine, the entire engine will be ruined.
The solution to this problem is a bypass valve. The bypass valve which sits somewhere in the middle of the piping will protect the water from getting into the intake manifold. While water trys to travel to the intake manifold, it will drain itself at where the bypass valve will be. This will help protect the car from any damages that the rain might have for the car.