smashup vs wrack-up

smashup

noun
  • A violent collision involving one or more vehicles. 

  • An instance or the result of smashing; that which has been smashed into pieces. 

  • An abrupt, damaging breakdown or failure. 

wrack-up

How often have the words smashup and wrack-up occurred in a corpus of books? (source: Google Ngram Viewer )