This is a thick resin casting of the spaceship from "Flight of the Navigator".
This was cast by a Hollywood FX artist from a mold of the orignal Disney studio model that was constructed for the movie. It is thought that the original made-for-production studio model was not actually used (a CGI ship eventually taking it's place), but this has not been confirmed and a miniature may have been used in some scenes.
After cleaning up, filling and sanding, it was sprayed with automotive paint and waxed to a reflective shine.
