I have a 2019 z800 trail. I decided to check my air filter after reading NMK's posts. At 105 miles it was plugged solid. I changed to a UNI filter, and made a similar enclosure, (pizza box), out of flexible plastic, and sealed it with duct tape, around the intake between the seats, to force the air to come from the cabin area. I now only clean the filter every 500 miles, and it is not very dirty.