Sure, why not? I have thrown a few butts out on the road in my time. So, since we are being so honest, tell me have you ever littered?
Let's add fast food wrappers, beer bottles, caps, cans, garbage of all types on your survey. Don't forget the disposable diapers, candy wrappers, and gum wrappers as well. By your logic, "virtually anyone" who eats or drinks while driving tosses the garbage out the window.
So not in memory, I haven't. I consider littering, like smoking and other public rudeness, beneath the dignity of a civilized man. In fact my sons would tell you that wherever I go, I make a point of picking up other people's litter. I ALWAYS leave a place cleaner than when I found it.
But I draw the line at cigarette butts -- they're too disgusting to touch.
Does puking count? I did that once or twice in high school, but that was involuntary.
But thanks for proving my point: smokers are by and large un-civilized jerks who go about fouling other people's air and environment.