backflip vs handbrake turn

backflip

noun
  • a total reversal in policy or opinion; a volte-face, a U-turn. 

  • An act of rotating one's body 360 degrees in the backward direction. 

verb
  • To perform a backflip (rotation of body). 

  • To completely reverse a policy or opinion; perform a U-turn. 

handbrake turn

noun
  • An abrupt change of opinion. 

  • An automobile driving manoeuvre where the driver starts turning the vehicle and then pulls on the handbrake to make the rear tyres lose adhesion and thus cause the back of the vehicle to slide around (in the direction of the turn). 

How often have the words backflip and handbrake turn occurred in a corpus of books? (source: Google Ngram Viewer )