Bob Grant, playing bus conductor Jack, had actually worked in real life as a bus conductor in order to pay his way through RADA (the Royal Academy of Dramatic Art).
The Royal Windsor Safari Park went into receivership in 1992 and the 150 acre site was chosen for Legoland's 2nd park, which opened in 1996. Lego sold the park in 2005 due to rising losses and it is now run by Merlin Entertainment.
Again there is much product placement on display: Jack places his bets with Ladbroke's (as seen on the side of both his bus and the Safari Park Special), whilst Mrs Butler is partial to a Guinness, as advertised on the No 12's side.
The section of the film featuring the new radio control system was a story element taken from the "Radio Control" episode of the source TV series On the Buses (1969) [See: Radio Control (1970)].
Movie posters for the picture featured a cartoon caricature collection of characters from the movie including an ape, lion and giraffe inside the safari bus but in truth the latter animal never is seen on the bus.