Another good idea is to have a portable ashtray for in car smoking! I have one and it's convenient instead of tossing them out the window you can just out them and then dump the ashtray whenever it needs to be emptied. Below is a website that features car ashtrays.
And, bare with me for one more second as I introduce a a FREE ashtray made from OF COURSE, recycled materials =) Below is a video that shows how to make an ashtray from an aluminum can.
Now, you have no reason to throw cig butts out of your car window!!!