I use a Fiberglass telephone splice box, converted for exhaust and intake with plywood under it. Was free and works great, it sat and run thru 3 hurricanes in Fl. a few years ago. I do not like the idea of my gen getting soaked could turn out dangerous if a short develops, also I would never put in under the trailer alarm or no alarm. Now I just sit it in the bed of the truck and a piece of plywood over the bed area where the gen sits and if possible move the truck away from the trailer because of the noise which is not too bad on the Champion.