2005 Tiffin Allegro Bus 40 QPD-engine bay part?

[cjthedad]

in the engine bay just inside the rear cap if you reach up the is a black plastic closure piece that covers the area between the rear cap and the interior space wall. Above it is filled with a foam block. The passenger side had miss formed and fallen from heat I assume (trying to get to taillight). When I removed it there was more silty dirt above it then I could have ever imagined and the foam is full of dirt I sprayed it with air to remove as much as I could. My question is. Is this piece necessary, will the foam fall out if it is not in place. I called tiffin parts and it is not a part they have. They said it was a custom part off the line, which I find interesting. Any insight would be helpful