Other mistake: Whenever you see the gates to the yard during the show they are painted green and have a "Wright and Boston scrap metal merchants" sign written on them. But right at the front of the opening titles of every episode, the gates are plain green with no sign-writing on them.
Here Come the Double Deckers (1970)
1 other mistake in Season 1 generally - chronological order
Starring: Peter Firth, Brinsley Forde, Gillian Bailey, Michael Audreson
Audio problem: Billie says her line "he needs a new image" without moving her lips.