Actually I just attempted making a splash shield yesterday for the filter.
When its finished i will post pics of the results. So far Ive cut sheetmetal and placed it under the bottom of the bumper- ( under were the stock side mount would be.) Then i need to go to a junkyard and get a stock fender vent piece in which mines doesn have one. ( the black fender piece that sits directly in front of the tire that would hide a smic.)amd them im going to put like patio screen in it from the front bumper ( only on the side pocket directly in front of the filter, not putting screen in front of my fmic.) and maybe that will lessen the water coming thru the front.
Therefore the back , bottom and both sides will not allow any water thru and the front will block it enough with the patio screen ( which will not be very visable.) ...Follow me? Damn im not good at explaining stuff like that online lol.