Solved - NEH 728: Datsun 240Z proposal with removeable hardtop - 1966

[Carnut]

What's this car exactly and when was it built, for 1 point?

[diecastaussie]

Its an early prototype design for the Datsun Fairlady Z or 240Z probably dated around 1965 or '66

[Carnut]

Its an early prototype design for the Datsun Fairlady Z or 240Z probably dated around 1965 or '66

Yes it is.  It's from 1966.
Just to answer the question fully however what distinguishes it from the other proposals from around the same time?
Locked for your reply.

[diecastaussie]

I believe that it was the first convertible/hardtop proposal and the first to have the "unique" Z car sloping front with scalloped/faired in head lights.  Previous concepts were all coupes and had typical Datsun sedan type fronts

[Carnut]

I believe that it was the first convertible/hardtop proposal and the first to have the "unique" Z car sloping front with scalloped/faired in head lights.  Previous concepts were all coupes and had typical Datsun sedan type fronts

Yes, the fact that it was a convertible is what I was looking for, so the point is now yours!
Well done.