they did say that they would like a ban on smoking at homes with kids, but it's unenforceable, thus the least they could do is ban it in cars where it would be more visable if someone broke the law
also, cars are a lot smaller than most homes, thus smoking is confined to a much smaller area. imagine the smoke from two adults in the front seat with the windows closed because it's winter, and the impact that could have to a young kid in the back
i think many people would like to ban smoking, after all the majority of people don't smoke, yet a minority of people smoking near non smokers can have an adverse effect, but the logistics of such an immediate ban would be difficult to implement
if there are continued restrictions on smoking, such as advertising ban, restrictions on sales (ie. no point of sale advertising, fags kept under counter), public smoking ban, it can only serve to reduce smoking overall, and help eliminate future generations from starting to smoke, so effectively smoking may die out over time. it's a horrible addiction that kills people and makes others feel uncomfortable or ill, even if they don't smoke themselves, so if a stop can be put on new smokers, whilst existing smokers can feed the addition in private in their own homes without bothering other people, both sides win