Here is another image from the Rolex 24 at Daytona International Speedway.  Watching cars go round and round does not present many ways to vary the composition.  I was walking around the track and noticed the flagpole and the Daytona logo and thought those would add some interest.

I started with some slower shutter speeds such as 1/100.  Looking at the image on the monitor on the back of the camera to check the image, I had to keep increasing shutter speed until I reached 1/2500.  Because it was overcast, I had to bump my ISO up to 1000.  I took several images that looked good on the monitor and went elsewhere.

If you zoom in on the image, you can see that the corvette is still soft.  What I took away from this is that if the shutter speed looks good on the  camera monitor, take several more images with a faster shutter speed, just in case.

Besides the sky being so gloomy, the above image is another case where I just missed the shot.

Daytona International Speedway: N29 10 46.85 W81 04 14.91