Yuppers they are based off the corvette with extensively modified panels and paint. A Japanese company made around 100 of them and sold them off for 150k U$ each I IIRC. They will be using a couple of those replicas in the speed racer movie due out next summer, by the same two fat guys that did the matrix!
Especially if it has the 7.0 liter corvette z06 under the hood! That was the last japanese car done right! The Mach 5 from the cartoon from the 1960'* was v12 engine, fast forward to 2007 and the Japanese are still mystified by a V8!