caravan vs landau

caravan

noun
  • A furnished vehicle towed behind a car, etc., and used as a dwelling when stationary. 

  • A convoy or procession of travelers, their vehicles and cargo, and any pack animals, especially camels crossing a desert. 

verb
  • To travel in a caravan (procession). 

  • To travel and/or live in a caravan (vehicle). 

landau

noun
  • A style of automobile based around the design of landau carriages. 

  • A type of lightweight, four-wheeled carriage in which the front and back passenger seats face each other. 

How often have the words caravan and landau occurred in a corpus of books? (source: Google Ngram Viewer )