REGARDING this quote: 
  
i have a socket at the front of mine. passenger side, below the cup holder need to pull the flap down as with the 1 between the seats. 
.................. 
  
pics please, i cant find them. 
  
Also, i have had the rear plastic comparment apart i think you coud fit some rear seats in like a set of small porsche bench seat. The chasis is the same as the G35 skyline aint it? That has rear seats,the Z's drivers seats fold forward too   
  
Might give it a go