wheels vs winter rat

wheels

noun
  • An automobile or other vehicle; a set of wheels. 

  • Well-developed thigh muscles. 

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 wheels and winter rat occurred in a corpus of books? (source: Google Ngram Viewer )