@evildictaitor: But inflicting physical damage onto your teenager is.
You can argue before the courts that she full well knew that is was harmfull to all occupants.
Hang on - are you for or against smoking in cars where children are inside being illegal? Just a second ago you were quite clearly stating that it shouldn't be illegal. But now you are saying that since smoking in a car clearly causes harm you should be able to take him/her to court.