During filming, the producers announced that this was the biggest family film to be shot on UK soundstages since " Chitty Chitty Bang Bang".
Every vehicle shown in the film is a Morris 1000 Minor. Even a custom-built 'stretched' limo.
Steven Spielberg was first approached to direct this movie. But he turned it down because he felt that the gross out humor was too over the top and didn't fit in the story and he was also too busy working on The Lost World: Jurassic Park (1997).
This is the second time Hugh Laurie and Mark Williams star together. They first starred in Disney's 101 Dalmatians.
Jim Broadbent who plays the father borrower, Tom Felton who plays Pea Green, and Mark Williams who plays the exterminator have all starred in the Harry Potter movies.