Cigarette smoke

That is very bad and one of the reasons I wouldn't allow anyone to smoke in my car. The odor is bad enough and then having to deal with the after effect of that scent and the stains to my car interior would just be horrific.

 

I do smoke but never in my car. It's very hard to remove the smell, as well as those stains caused by the smoke itself.

 

Indeed. There are techniques to remove the smoke smell, but its neither easy or inexpensive.

 

This is just nasty. Good thing I don't smoke and I don't allow any passenger to smoke inside the car.