I agree I think it is a good idea but, as phoenix says I think it would be very hard or impossible to enforce. The police have a very hard job to do now, have they really got time to follow cars to see if people are smoking? They don't really manage to stop people using their mobile phones so what chance of this? Nice idea though, I do not understand why people do not see what damage they are doing to their children, you might occasionally see someone with the window open but not when it is raining and.......well, say no more, when did it not rain recently?