you can probably make a home made one with dryer ducting from the hardware store

 

I ordered the JLT insert as I am an OCD car washer. This weekend I took the hood blanket down from the underside of the hood looking for an additional solution. I found a sheet of grey 3/4" packing foam inside a box that was shipped to me in the past, cut some brick shaped pieces the exact size of the "grilles" in the heat extractor, then superglued them to the inside of the extractor grilles as sort of a filter. I am going to install the JLT plug as a secondary stop and see what happens the next time I wash the car. I dont want ANY water in the AIRBOX as the water here in Indiana might as well be solid calcium. It leaves huge mineral deposits on anything it is left to dry on and would probably bake into the plastic of the airbox making it look like $hit... I think if we could somehow close the front-most slit in the extractors, we would be golden as it is where I think most the water gets directed to the air filter....