Appropriate payback for flicking butts?

[sparr]

I was driving down the street (Ponce, near Briarcliff) on my scooter and someone going the opposite way flicked a cigarette out the window that hit me in the arm. Imagine my disgust and annoyance (imagine if it hit me in the face...). Now, what might be an appropriate response to this? I was considering picking it up, turning around, and throwing it back in their window, or possibly throwing something equally nasty (to them, as their cigarette was to me) in. Thoughts?