Yeah it's more of an evolutionary change than from the C4 to the C5, but the C4 came out in 1984.

Now if only they made a fixed-roof version of the fastback body style, that would be nice. Hopefully the Z06 will be that, plus have something like 450 hp or so (perhaps 500 to compete with the Viper?). Either way, the performance of the thing is getting more and more phenomenal even in comparison to the rest of the market.