auto vs winter rat

auto

noun
  • An automobile. 

  • An autorickshaw. 

  • A setting for automatic operation. 

  • A car with an automatic gearbox / transmission. 

  • An automatic gearbox / transmission. 

winter rat

noun
  • An old, unattractive automobile, purchased for little money, to be driven during brutal Great Lakes winters while the owner's "good" car remains garaged and protected from corrosive road salt for the season. 

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