diner vs dining car

diner

noun
  • A dining car in a railroad train. 

  • A typically small restaurant, usually modeled after a railroad dining car, that serves lower-class fare, normally having a counter with stools along one side and booths on the other, and often decorated in 50s and 60s pop culture themes and playing popular music from those decades. 

  • One who dines. 

dining car

noun
  • A carriage on a train that functions as a restaurant. 

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