Factual error: Just before Walther Matthau meets Susan Sarandon for the first time in her dressing room in the movie theater, he passes a poster for "All Quiet On the Western Front" in the hall. "All Quiet On the Western Front" wasn't made until 1930 and this film is supposed to take place in 1928.
Factual error: One of the main characters has a Harley Davidson. The movie is supposed to take place in the fifties. The Harley had an electric start primary cover which wasn't made by Harley until 1965.
Factual error: In the scene right after pinback shoots the beach-ball alien, we see the Dark Star space craft cruising past a planet with a sun in the background. You can see a reflection on the planet which is coming from the space craft. I'm sorry, but usually ships in space are not large enough to reflect off a planet, especially to the degree this one does. (00:48:20)
Factual error: The movie is set in Transylvania, but the natives all speak German and with German accents (probably an homage to the book, but still incorrect). (00:14:30)
Factual error: As Kennith Williams and Bernard Bresslaw approach a notice board on horseback, you can blatently see the road they are on. You can even see the white hazard lines on the road. Apart from anything else, Tarmac wasn't even invented until 1901 yet this episode is set in 1750. (00:12:30)