Smoking and Ghostbusters

I watched Ghostbusters last night - I knew it pretty well as the kids when they were young watched it in endless rotation but obviously things have changed since then and one of the things that seemed out of place was all the gratuitous cigarette smoking - in the car - after the battle - all the characters were puffing away like they were sponsored. I am not anti smoking - I smoke myself but I sensed something strange - so searched the above title on Google - and lo and behold - Jason Reitman - son of Ghostbusters director Ivan has done a movie about smoking - Thank You for Not Smoking
Here's an article on director growing up on film sets - smokey ones perhaps?