The unmarked Commodore police car which arrives at the house has hubcaps. All Australian police cars - marked or unmarked - use pursuit rims, with no hubcaps.
Scarman is the character from the movie-within-a-movie Hot-Blooded. He should only know that he's a serial killer, not a supernatural force brought to life. But he tells Detective Lucy Carter, "I'm something special." This indicates that he knows exactly what he is.