Since the first video of the purported ZL1 prototype videos were posted, Camaro6 members have been turning up their volumes to listen for a supercharger sound. Assuming both a ZL1 and Z/28 are planned for the 6th gen Camaro, a supercharger sound would make this prototype the ZL1, while the upcoming Z/28 is presumably naturally aspirated.
In this video, a supercharger’s whining noise is clearly audible, which makes this likely the ZL1! Check it out inside.