Short answer: prototype testing.
A few months ago, insider sources confirmed that Chevrolet is really doing it this time. No joke. The next Corvette is going mid-engined. Performance wise, engineers have done all they can with the front-engined setup, as evidenced by the new Z06. Just as shocking is that it's entirely possible a C8 concept will be shown at next year's Detroit Auto Show. Yes, exactly one year from now. Chevy wants the C8, specifically the Zora ZR1 flagship, to be in showrooms less than two years from now.
The C7 will remain in production until around 2020 once the rest of the C8 lineup is launched. So what's currently happening with the project? From what we've been told, official prototype testing has begun. Sources having confirmed that Chevy has driven a test mule wearing a Holden Commodore Ute body with a large rear wing and various other aerodynamic aids. But what's really hiding underneath that truck bed is a V8. It's really an ideal way to disguise the C8. Car and Driver has also learned that the C8's wheelbase is expected to be nearly eight inches shorter than that of the C7's. The reason being is that the transmission has been moved "from ahead of to behind the rear axle."
A shorter wheelbase will allow for improved steering response and a tighter turning circle. What's more, the C8 is also being engineered to handle smaller V8s, figure around 3.5 to 4.0-liters. Translation: no pushrods. Indeed, the Corvette is about to experience the most dramatic update in its entire 60+ year history. Get ready.