I'm a smoker myself and I wouldn't dream of smoking in someone's car whether there was children in it or not. But I think to ban people within their own cars from smoking is a bit uncomfortable for me, not as a smoker, but just as you mention, when talking about people's rights. What would be the next move - banning people from smoking in their own homes on their own property? What I would like to see is a very strong campaign to educate people and really push to get them to give up smoking voluntarily in front of children at all times, not just when in a car.
Don't get me wrong I do understand the dangers of smoking and in particular to those non-smokers. I never have and never will smoke in front of people who don't smoke and that's whether they say it's ok or not. But I honestly think that sometimes the anti-smoking campaign can resemble a bit of a witch hunt at times. When we consider how many deaths are caused by alcohol for example - innocent people getting smashed up in cars, knocked down, murdered, not to mention the health risks I don't see the same moves to ban alcohol. When we see how many diseases such as asthma can be attributed to traffic pollution, I don't see huge campaigns to ban people from driving - but then I guess that's political suicide to go down that road for some as it wouldn't be popular - but smokers are an easier target. I think if we are going to clean up our act then everyone who is involved in any kind of pollution or health risk to other people should be involved.