This sounds kinda crazy, but i found that if you get a glass and fill it maybe halfway with white vinegar, then leave it in there for a day, it will get the smoke smell out, and your car will smell like vinegar for a few days (which will fade out), but it will get rid of the cigarette smell. This also works with ammonia, but ammonia is WAY more potent smelling and can cause gagging and such.
The next way, which you may not be so skeptical about is baking soda, which should take the smell away after a few days.
And then if you want to spend some money to get rid of the smell you can get this stuff called Ozium, which i have heard works very well.
http://www.atmosphereproducts.com/product_images/ozium/