Well I used to smoke and I always used an ashtray, I never tossed a butt out the window. For one it is littering and I hate littered streets and trash everywhere! And two, it can start serious fires, especially if near a forest. Every car comes with an ashtray, so there is no excuse. Heck the car I drive now has a really sucky ashtray, because it is very small, but deep. So eventually when it gets full, there will come a time that when you go to put out a cigg, you end up instead setting the butts in the ashtray on fire. A nice deep ashtray works great for smoldering fires LOL. And of course most butts are just filters, so it is burning filters. The smell of burning filters is really unique, like burning hair, and equally gross. Anyway, when I smoked I had a large ashtray that was heavy so it wouldn't fly around when I made a sharp turn, and I had it sitting on the passenger seat next to me. No filter fires with that. WAs easy to put out a cigg while driving.
So I don't think all smokers do it. Some people just don't give a crap and are litterers and some are not. LOL, for instance, on my way to work there is this point where I have to enter a large left hand turn lane. Light for that lane is on a pole. Median strip is pretty large and to the left of me. Every week or so somebody has been putting their banana on the median strip. Each day on my way to work I see it more and more deteriorated. Eventually it will disappear....only to be replaced again a few weeks later wth another fresh banana! LOL, what's up with that? It's littering and a waste of a good banana dammit!
