I bought a used van and the lady smoked in it like crazy. Bought this spray called Ozium and one spray killed the smell. You don't want to inhale it, so spray a shot in the a bag etc and leave for awhile, don't breathe it when you open the bag either. I take my dad shopping a few times a month and he smokes in my van, I spray a shot at night and the next day the smell is gone. There is an after smell but it goes away fast.
Thanks! I bought some of the gel cannisters from Amazon. Promising reviews.