Lots of help here for the rears :-  http://www.350z-uk.c...se#entry1089809 
  
And page 5 post 86 here for the fronts :- http://www.350z-uk.c...-7/page__st__80 
  
flexib is right, I did do a guide http://www.350z-uk.com/topic/72441-replace-the-front-bose-speakers-with-alpine-65-speakers-spacer/page__hl__speakers