Rolls-Royce vs cream of the crop

Rolls-Royce

noun
  • A car made by this manufacturer. 

  • Anything that is the best of its type; the best quality product possible. 

name
  • any of several British companies that make motor cars, aero engines, etc. 

cream of the crop

noun
  • The best or most desirable among some selection. 

How often have the words Rolls-Royce and cream of the crop occurred in a corpus of books? (source: Google Ngram Viewer )