motorcycle vs passenger car

motorcycle

noun
  • An open-seated motor vehicle with handlebars instead of a steering wheel, and having two (or sometimes three) wheels. 

verb
  • To ride a motorcycle. 

passenger car

noun
  • A motor vehicle designed to carry (a few) passengers; a motorcar. 

  • A railroad car designed to carry passengers. 

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