I have replaced the stock air box with a Stillen Hi-Flow Air Intake at 40k miles. I bought the car when it was at 36k fully serviced. This is the pic of the OEM paper filter:



I am not trying to make any point here, just thought a visual representation would be good.

On the side note, if the aftermarket intake is not covered with plastic like the OEM one, how dangerous it is for the intake to suck water from the underneath or during rains or any case that can cause water to get inside?

 

I have a Stillen intake and I haven't had any problems yet but I avoid driving into huge puddles, lakes and rivers.