Experimental C8s currently reside in Building 54 (a.k.a. Area 54) at GMs Milford, Michigan, proving ground. Since we nabbed aerial photos of one test mule two years ago, prototypes seldom leave the building during daylight hours. GM owns two Ferrari 458 Italias for benchmarking, and the company once had a McLaren in its benchmark fleet. Also owned by the General: a Nissan GT-R, two Porsche 911 Turbos, and a BMW i8, any of which may be being used to aid in C8 development. So focus your eye-in-the-sky cameras on coordinates 42° 35 11 N and 83° 41 10 W
Quad cams just screams ZR-1 for the 2019 power upgrade. So I'm assuming all there will be is a base-version initially, and then they'll follow up with the ZR-1.. a mid-range Z06 somewhere along the lines perhaps ?