The 1997 C5 Corvette was the first redesign of a Corvette since 1984. That means designers had two options: They could be conservative or they could be radical. They erred more towards the conservative route. But there was one radical design in the mix that got the boot.
One of the proposed designs for the C5 Corvette eschewed the traditional oval tail lights for diagonal rectangles. There were also four centrally mounted exhausts and a taut fastback design. It also has the diagonal fender vents that are seen on the C7.
Other than similar exhausts, these features didn't appear on the C5 Corvette. The rear of this computer generated design was deemed too radical and was shelved. If it was proposed for the C6, it was shelved then too, presumably for being too radical again.
But now we have the 2014 Corvette, and guess what? We have diagonal rectangular lights, I guess they're technically rhombuses (rhombi?), a very taut and athletic fastback shape, and diagonal vents at the front. I guess after sitting on it for 17 years, it finally didn't seem that outlandish.
(Hat Tip to @chrisdraper2007!)