Chevrolet refuses to admit what we all know: the existence of the upcoming mid-engined C8 Corvette. As it stands, it's the industry's worst-kept secret. Even during this writer's one-on-one conversations at Detroit last January with Corvette chief engineer Tadge Juechter was the subject promptly pushed aside. "All in good time" was the best response we could get on the subject. Fortunately spy shots and this latest spy video, first published by Corvette Blogger, all but make official the C8's existence.

At the moment, we're not 100 percent certain what'll power the first-ever md-engined production Corvette, but we have a very good idea thanks to various internal leaks: a twin-turbo V8.

And now we can hear that suspected engine for the first time, albeit briefly, in this new spy video taken by YouTube user Big Ersk. He just happened to be driving somewhere the other day when he came across a pair of pickup truck prototypes that were part of a convoy. Naturally it caught his attention, and then he saw it (at 5-second mark): a camouflaged mid-engined coupe. It can't be anything other than the C8, right? Probably not. Then again, rumor has it Cadillac is also working on a new halo car, though we doubt that's what we're seeing here. Later in the video, at 1:12, you can hear the prototype's engine as the driver hits the gas to get away from his YouTube stalker (who chased the prototype for 10 miles).

Could that engine be the rumored 4.2-liter twin-turbo V8, or could it be the also rumored 5.5-liter V8 with around 850 hp? Remember, Cadillac just unveiled a new twin-turbo 4.2-liter V8 with 550 hp for the CT6 V-Sport, an engine that's supposedly brand-exclusive. We'll see. In any case, let us know what you think is lurking behind the driver and passenger seats. And while we're at it, anyone care to take a guess what those prototype trucks are? Our guess: the 2020 Silverado HD.