The Ferat rally car used in the film was in fact a prototype for an unreleased sports model Skoda 110 Super Sport produced by Skoda Auto, now generally referred to as the Skoda Super Sport 'Ferat Vampir RSR' in homage to the film. White version of it, without 'vampiric' elements, made a brief appearance in earlier film Tomorrow I'll Wake Up and Scald Myself with Tea (1977).
Despite various mystifying stories about 'censorship' spread by Juraj Herz, the final cut of the film lacks only two scenes - one three seconds long shot of a dead body in a coffin (which was replaced by a shot of a coffin filled with dirt) and a longer animated sequence showing the 'guts' of the vampire car's engine, created by Jan Svankmajer. Everything else remained exactly as it was intended and filmed.
In 1962 Josef Nesvadba published a short story about a car powered by the driver's blood, called 'Vampire Ltd.'. Barrandov Studios immediately secured the film rights as part of an intended series of three horror adaptations of Nesvadba's stories to be made in co-production with American producer Samuel Z. Arkoff. 'Vampire Ltd.', written and directed by Pavel Hobl, was to be the first of these. The next film in the cycle was to be an adaptation of Nesvadba's short story 'The Second Island of Dr. Moreau', written by Milos Macourek and directed by Oldrich Lipský. However, the American side found both scripts "too arty and too bloody" for the American market and its strict rating system, so the co-production was dropped and the third film of the trilogy was not even developed. In 1967, Nesvadba himself wrote a new script called 'The Blood Red Car' and sold it to another American producer Ivan Reiner, who ultimately did not produce the film either. Uncertainty about who currently owned the rights led Nesvadba to writing a brand new short story on the same topic, 'The Vampire Twenty Years After', which he published in a Tvorba magazine in 1972. At this point, Juraj Herz came into the project and wrote a synopsis for his intended television adaptation of this later story, entitled 'Racing with Death'. After further peripeties, with the material being re-adapted by several other writers and for several other directors, it went back to Herz on the recommendation of Milos Macourek, who wrote the screenplay review, and the film was finally produced, 20 years on from the original intention to do so.
The company producing the blood-sucking car was called Vaduz in an earlier version of the script. The renaming to Ferat was for two reasons. Firstly, the name evokes the car companies Ferrari and Fiat, which corresponds with the film's intention to comment sarcastically on the efforts of multinational corporations to 'suck the life' out of their consumers. Secondly, the resulting Czech title 'Upír z Feratu' evokes the title of the classic vampire film Nosferatu: A Symphony of Horror (1922), whose Czech distribution title is 'Upír Nosferatu'.
The character of the psychiatrist, with his line about a fellow doctor who already wrote a story about biological cars twenty years ago, refers to the author of the short story the film is based on, Josef Nesvadba, who was a graduate of the medical faculty of psychiatry.