A couple of photos show that a 1968 Camaro Z28 was used as the pace car for the 1968 Glen 500 Trans Am race held at Watkins Glen Grand Prix Race Course, Watkins Glen, New York on Sunday, August 11, 1968. Notice the car is not a Rally Sport and that it has white stripes, bumper guards and the spoiler package.
This is one of the few races in the 1968 Trans Am Championship season that Mark Donohue didn't win in his Penske Camaro. Jerry Titus won in his Mustang followed by Sam Posey in second and Donohue in third, both driving Penske Camaros.
CRG member Mike Scott (Group/7) sent me the first picture several years ago and he said that he found it on the internet many years before that. I did a search for it but could not find where it came from.
The second picture came from the Revs Digital Library. You can just see the back of the Z28 underneath the Dunlop start/finish line bridge. Click on the link to use the magnification tools:
https://library.revsinstitute.org/digital/custom/single-image?id=330922&collection=p17257coll1Third photo is a cropped version of the second photo.