Without the EXIF data it is impossible to say, but there is nothing sharp in your image, if you had a good fast shutter speed, the vehicle was stationary, no crappy filter, it isn't a huge crop, etc then I'd say you have a soft lens, but to test that you need to put it in a tripod and do some controlled exposures in both manual and auto focus. It does not look like a micro AF issue as nothing is sharp, not meaning you don't need to do micro AF, but that the issue you have is masking any additional micro AF issue.
Here is how I test my lenses for sharpness and element misalignment. This series showed me extreme misalignment at 35mm with a 16-35, even at this size you can see the image right paper is more blurred than center and left.
And a little sharpen and rework on your elephant shot too.