Stop in for a cup of coffee

its not that important to me, but my exhaust system consists of about 3 inches of pipe out of the manifold. basically underneath my feet.
there are a lot of holes in the trunk floor and kind of need something that will keep the fumes back there since I took out the rear seat.
My ultimate choice would be sheet metal and sound deadener.
The 1/4” mohagany plywood is about the best availabe choice for me.