Next Z to be unveiled in 2013 Tokyo auto show.

andyj

This is just a guess, but I would say close to production model. I think when they talk about concepts, they are referring to a car that they are considering building in the future, but haven't made a decision whether to build it or not. And from what I read, a concept car also can be intended to hint at a design or style direction they are considering for the future, and showing the concept is in part to gauge public response. If the new Z is scheduled to come out in 2015, a year or less away, they would have to be very close to the final design and specs. Like I said just a guess.