A white 1968 Camaro RS/SS convertible was used as the pace car for the Atlanta 500 NASCAR Grand National event held at the Atlanta International Raceway in Hampton, Georgia on Sunday, March 31, 1968. Cale Yarborough won the event in his Wood Brothers Mercury Cyclone.
The only photographic evidence I could find appeared in a section of an old automotive themed television show called Car and Track. The color footage from the show gave a split second shot of the Camaro coming down pit lane after the field got the green flag following a caution period. I have copies of these 1960's/1970's television programs on VHS from when they were rebroadcast by Speedvision back in the 1990's but I was able to find the portion concerning the 1968 Atlanta 500 posted on Youtube:
https://www.youtube.com/watch?v=WwelbscvAIA The Camaro pace car can be briefly seen in pit lane at 6:05.
Unlike the previous NASCAR Camaro pace car graphics at Daytona, Bristol, and North Carolina the Atlanta car seems to lack the large red and black striping on the sides or hood.
If anyone has better pictures of the Camaro that paced this particular event please share.