Here is a picture of the 1968 Camaro RS/SS 396 convertible that was used to pace the World 600 NASCAR Grand National event held at Charlotte Motor Speedway in Charlotte, North Carolina on Sunday, May 26, 1968. Buddy Baker won the race in his 1968 Ray Fox Dodge Charger.
I found the picture on page 17 of the official souvenir program for the event. Under the picture was a caption that states the following:
"Officials of Charlotte Motor Speedway have selected the Chevrolet Camaro as the Official Pace Car for the Ninth Annual World 600. The Camaro, furnished to Charlotte Motor Speedway by Chevrolet Division of General Motors Corporation and LaPointe Chevrolet Company of Charlotte, was selected because of its 'direct reflection of the many features found in grand national competition which have been translated into the street automobile.' The Official Pace Car has been specially equipped with the new Firestone radial-ply Wide Oval tires with safety shield inner-liner."