Back when I had a tacoma, I put a deck plate on the stock air box.
They have a cover that screws on with a o-ring type seal if you are going to a muddy place.
I usually left it open when driving on the highway even on rainy days and never had moisture in the air box.
just a thought.
if you live anywhere near the water, you can get these for about $5.00 at any boaters supply store.
For you inland guys, maybe
ebay, or the interweb.
there is a lot of info on this mod over of TTORA website.