I asked Nissan and they said yes, actually the salesman say "little seats, little legs, no problem"
Took it to the child restraint joint and they said I was kidding myself.
I was going to make a frame up to support the seat (KC seats too short so baby seat rocks around) and have a spot for the restraint to clip to.
The mrs would't hear tell of the new baby being held in place by some bodged up home made contraption that the restraint joint wouldn't even consider, so I traded on the STX 550.
Also I think the baby seat might be too long to go in as there isn't much room in there, my daughter (18months) touches the back of the passenger seat with her feet in the dual cab when the seat is in a comfy spot, king cab a fair bit shorter