I use the under battery intake with out the stone guard under the front bumper as my car never came with one. No issues with driving in the rain or through puddles but I did drive through a very deep puddle one day which was a bad idea but I risked it. Idled through fine but the air filter was full of water so as soon as I accelerated, water went in the intake and the car ran like crap. Had to tow the car home (which was only around the corner) and dry out the cooler and piping. Learnt my lesson the 1st time.