Here for you.
You should probably hang out here.
http://www.skylinesaustralia.com/forums/topic/412530-new-new-whoretown/
It's where the cools kids are.
Rear seats and seat belts need to be removed.
Any holes leading to the outside need to be plugged.
Needs a blue slip.
Don't know about fixed back seat.
Can't see why not.