While working the course at an autocross, I heard a metallic sound as a Z06 went by. I found a bolt that is about 3 inches long, and about 7-8mm in diameter (threads). The head of the bolt had some road grime on it while the threads were clean. And the end of the threaded section was rounded off (almost hemispherical.) Gave it to the owner thinking it may have been a ride height adjustment bolt (end of the spring), but later she said they (her husband and another guy) could not find where it went, but it is a GM bolt. Any ideas? I suppose it is possible she just hit the bolt that was already on the course.