That's one way of a getting a driver's attention!
My close encounter with a cactus was this. I knew I poked my finger but didn't realize the extent
until that evening when I held it up to the light and noticed a shadow under the nail...
![Cactus accident Nail12](https://i.servimg.com/u/f27/20/35/00/45/th/nail12.jpg)
FWIW it was a T.pasacana A fine-tipped tweezers shoved up the nail fixed it
![Smile](https://2img.net/i/fa/i/smiles/icon_smile.gif)