Toyota is trying to make Prius into a family of vehicles, not just the top-selling hybrid. At the North American International Auto Show this week, the Japanese automaker unveiled two new Prius derivatives—a smaller version and a slightly larger version. There is also a plug-in version of the Prius coming. And there is talk of a Prius-branded van, too. The problem, though—or the opportunity—is what to call more than one Prius. Priuses? Prii?
  It reminds us of an episode of Taxi in which the cast was watching a cable feed of a Delaware state legislature debate about whether to be called Delawarians or Delawarites. (Or, quick, what is the proper name for a flock of crows? Answer: a murder of crows.) Toyota's Lexus division has the same problem. Lexuses or Lexi? Ford CEO Alan Mulally has never sorted out the plural of Taurus. Tauruses or Tauri?
  In the video below, Toyota says the plural of Prius might be Prii, Priuses, Prium, Prien or just plain Prius. But they want your vote. You can head over to the Prius Web site and choose your favorite. Voting ends on Feb. 20. As of this posting, the early leader is Prii.