Holden, like a so many other car manufacturers, has come close to producing what could have been a legendary car only to pull out at the last moment. Its GTR-X design was reminiscent of cars produced by Lamborghini and Ferrari, with its wedge-shaped profile and concealed headlights. Running an inline six producing 160 bhp, the GTR-X was able to achieve a top speed of 130mph and go from 0-60 in 8.3 seconds. To keep costs down, the mechanicals were borrowed from the Holden Torana, and the six cylinder was chosen over an eight due to its economy and widespread availability. Interestingly, it would have been the first Holden to be fitted with 4-wheel disc brakes if it had gone into production. There are a number of reasons why the GTR-X never made it that far, including both competition from the Datsun 240Z and restrictions faced by Holden in export markets—and Australia didn't have a big enough domestic market for the GTR-X because of our small population base. So instead, it was the Monaro that became Holden’s first coupe in Australia. Check out this cool footage of one of the GTR-X prototypes being tested in 1970.