(1) 500 mph TAS at FL450 = 192 kn CAS. The ceiling is more impressive than the speed (if either is achieved).
(2) There is no FAA or JAA code for certification of public transport gyroplanes.
(3) If you take all the load on the wings, the unloaded rotor will probably flap and flutter itself off, especially at high speed. If that doesn't happen, it'll slow down, leaving the problem of spinning it up again at 150kn+. Ever heard of slender wing torsional divergence?
(4) If the Corvette engine is anything like any other American automotive Engineering, the power to weight isn't going to be all that impressive. Why on earth not use a tried and tested (if uncertified) lightweight aircraft engine such as a Rotax 914 ?
(5) It's very hard to co-ordinate a controllable elevator with a controllable rotor. I've never seen a successful gyro with anything more complex than a TRIMMABLE tailplane.
I love the concept, but can't help feeling that the practice leaves a little to be desired.
G