Oliver Wendell Holmes said, "Your right to swing your fist ends where my nose begins."
Now, if smoking did no harm to others, then by all means, I'd be all for you comitting suicide in whatever way you choose necessary. And I don't advocate creating "smoking laws" - the idea of creating a targeted law is exactly the kind of thing that gets us all in a lot of deep shit. We create laws that apply to "all cases, except where noted in subsections b., c., d. f.42, and this other law over here."
Get back to basics, I say.
Cut out all the crap, and instead pass a single environmental law that defines a maximum acceptible carcinogen output. I'll admit I'm pulling this idea out of my nether regions right now, so I'm not really sure how we'd benchmark that, but I'm sure something fairly reasonable could be dreamed up.
Then apply that standard across the board. You drive? It applies to you. You smoke? It applies to you as well. You piss in somebody's beer? Well, you've got other problems, in addition to the carcinogen law. :)
I'd love to have a solution without laws. The problem is, we're human beings. Anarchy is a great state, if all you've got is totally enlightened beings, which our species seems to be lacking in.
It might very well be that the carcinogen output from cars would completely blow away second-hand cigarrete smoke. I'm fine by that, and quite frankly, I wouldn't be surprised at all. Cigarretes do make me personally ill, and maybe specifically attacking them is wrong - but saying that we have a "right to smoke" without regards to those around us IMO is wrong.