I don't understand how water is getting inside of your airbox.
[My open air filter doesn't even get damp when it rains here. Not even a drop of water on its chrome plated end cap (during our worst downpours).]
The 'silencer' (actually, I think it's called an "air intake resonator" is buried inside of the fender. I had to remove a few screws from the left fender liner to get mine out (it helps if the wheels are turned fully left; or the left front tire/wheel is removed entirely). After you bend the fender liner down, and look inside the fender (toward the front of the car) you should see the 'silencer'. It's made from black plastic (same plastic as the airbox).
HTH
Mike
