I had my rear fender primed and I decided to use some rubberized undercoating on the underside of it. I thought it might look good and protect it since I have a bad habit of riding down gravel roads.
I taped off the outside of the fender and proceeded to spray away. This is it before the spray:
This stuff has a strong odor. It was also kind of messy. I hope I don't regret my decision to use it.
Here's a pic after spraying: