I use a template tool and make the floor in 2 pieces (lengthwise). Once you get a good fit you can push each piece tight against the side and then mark them for the center cut.
On the last one I did I used split black hose to trim the edges where the floor meets the side panels.
Best would be if you can figure out a ledger for the floor to rest on and be screwed to but that may be difficult because of the soft panels... |