Quite accidentally I did find out what this was.
The windscreen and glass sorted of reminded me of a Lancia Stratos:
Bertone, the guy who designed the Stratos, had also designed and built a futuristic looking wedge as a one off concept called the Stratos Zero.
Aha I thought to myself, I know what Bob's posted. I'd better just check first:
A wonderfully sexy looking beast for 1970, but it wasn't the car in Bob's picture.
Happily though Google spat out a picture of another wedge-shaped Zero, this time a Dome Zero:
A 1975 Japanese take on a supercar. I love the way they seem to have borrowed ideas from other cars of the era. The nose looks distinctly Ferrarri 365 BB:
Things seem to go a bit pear shaped the further you get to the rear - windows in the doors which turn into air vents etc.
Here's a bit of trivia for you though. Apparently the Dome Zero was used as the inspiration for the vehicle that Rodimus the Transformer transforms himself into when he gets fed up with clumping around on two legs and shooting at things:
Betcha didn't know that...