
The Port-o-Potty!
The doors open and close (but bring your own seat):

And you can dogfight in it (just don't go inverted or bad things might happen):

As a bonus, there's also the Black Hole, which probably sets the world record for the largest flying object in YSFlight.

Download them here: The zip file contains all my YS addons. I originally released this many years ago, but as the download links have gone away due to link rot, I'm re-uploading them.