Ford came to Earth for a week, and got stuck there for fifteen years, departing only when a fleet of Vogon constructor ships appear in the first episode, taking Arthur Dent with him. Ford is the source of much explanation of the weird universe that Arthur finds himself in; for example, the importance of knowing where your towel is, sticking a fish in your ear, and why the greatest cooks in the universe cook such bad food on Vogon spaceships. Ultimately, however, his personal mission is to find a nice party and get incredibly drunk.
Ford's life story diverges into alternative versions in the radio series, TV series and books. In the original radio series he finds himself dangling from a mile-high statue of Arthur Dent suspended in the air, and after surviving a fall from the statue he ends up stranded on the planet of the Ruler of the Universe when Arthur steals the Heart of Gold. At the end of the TV series, he is marooned with Arthur on prehistoric Earth. In the books, he survives a series of adventures including a present-day invasion of Earth by aliens and almost being choked to death by a severed hand in a sleazy bar, only to (presumably) perish along with all the other characters when all the alternative Earths are finally destroyed. However, the radio adaptation of the books holds out the hope that the characters have only been transported to Milliway's, and therefore have survived the final destruction of Earth.
Adams later observed that this joke was lost on U.S. audiences who assumed it was a typing error for "perfect". In the French version, Le Guide Galactique, Ford's name was changed to "Ford Escort". The joke is also now largely lost on younger audiences because of the disappearance of the Ford Prefect from frequent use. In the film adaptation, his last name was never actually stated on-screen, but it is given in the film's credits as "Prefect".
Prior art for Adams' satirical point – that humans attach such importance to automobiles that a visiting extraterrestrial might reasonably mistake them for the planet's dominant life form – can be found in a widely reprinted article from The Rockefeller Institute Review titled Life on Earth (by a Martian) by Paul Weiss. The idea was also expounded by Carl Sagan, though this may have postdated Adams' creation of the character of Ford. The 1967 Oscar-nominated animated film What on Earth! from the National Film Board of Canada is based on this premise.
Despite all this, his semi-cousin (they share three of the same mothers) Zaphod Beeblebrox calls him "Ford" the first time they are reunited in all versions of the story except for the film, where Zaphod addresses him as "Praxibetel Ix", then introduces him by saying "This is my semi-cousin, Ix...Excuse me, Ford". While not explained in the book, a footnote of the original radio scripts explains that "just before arriving (on Earth) he registered his new name officially at the Galactic Nomenclaturoid Office, where they had the technology to unpick his old name from the fabric of space/time and thread the new one in its place, so that to all intents and purposes his name had always been and would always be Ford Prefect.