At its announcement in August 1970, a month after the launch of the redoubtable Torana GTR XU-1, GMH said it was “breaking with tradition by giving the public an opportunity to see in advance a car which could be the basis of a limited production vehicle in the future…the GTR-X has been built specifically to test design concepts and help assess the Australian market for a locally designed and manufactured two-seater sports car.”
OH really, GM? Sounds like you were been sipping too much Pontiac Banshee!
src: cartype
IEDEI 
I like it, with the sharp line on the sides.
Hey, nice similarity of this Holden concept to the VW do Brasil SP2: http://www.vwsp2.ch/