give you a little story..

my cousin had a 97 maxima... MB Quart Components in the front ... MDX Sub in the rear... my 97 maxima had Diamond Audio M561's in the door.. Diamond Audio Hex in the rear deck... 2 ID Max 12's.... 1 Kicker 120 watt amp on the front and anotehr kikcer 120 watt amp on the rears and a 1000 watt kicker amp on the sub...

my cousin always told me rear fill was a waste.. and i ignored him.. i had my system sounding sweet.. till one of my kicker amps crapped out... then i was running fronts and subs... trust me.. rear fill is hype

 

I tried it with just the front, and it doesn't sound complete to me...I like the sound coming from all directions...but i gues people have their preferences...my rears are situated on the outside of the rear panel now...

 

i hate how close the Z's stock rear mounts are to my ear.. currently on the stock bose system.. i have a bias towards the front