Well, when I smoke in the car, I have my window halfway down, and I ash/blow smoke out the window. I also 'air out' my car after i'm done, by rolling down both windows for a couple minutes.
I do this because the cloth interior of my car sucks up the smoke smell, and if I had my windows up, it would completely reek. When I have the window down, and I 'air out' the car after I'm done, the smell is either gone, or close to it. A light, weekly febreze-ing makes it smell all nice and pretty inside (no lingering smell). I doubt that even a heavy febreze-ing would help much after years of 'windows up' smoking, when the smell has permeated the cushions.
Also, with the window down (and the 'air out' process), I (myself and my clothes) smell much less like smoke after I get out of the car, and am therefore much less offensive to non-smokers with sensitive noses.
Another reason I am trying to avoid having my car smell, is to help preserve resale value if I ever decide to sell it. A car that reeks of smoke will attract fewer potential buyers than a normal smelling car.
Hope this clears things up.
ebaycj