This is a great photo of the white 1968 Camaro RS/SS 396 convertible pace car lettered up for the 1968 Virginia 500 NASCAR Grand National event that took place at the Martinsville Speedway in Martinsville, Virginia on Sunday, April 28, 1968. Cale Yarborough won the race in his 1968 Mercury.
This Camaro was used by the track for multiple events during the 1968 racing season. Notice that in these pictures the car is wearing Goodyear raised white letter tires. Later in the year those tires would be swapped out for white sidewall tires. See my other threads for photos and information.
I spotted the photo in a recent post on the Pace Car and Truck Owners and Enthusiasts Facebook page. I did some research and found that it was originally posted on the Martinsville Speedway Facebook page back in 2018:
https://www.facebook.com/pg/MartinsvilleSpeedway/photos/