I did some with the little I had left. It's one of the reasons I want to get some more. On the doors I did 2 places. Right behind the speakers and in the center to change the ring frequency. I also put some on the passenger side fire wall, not where it gets hot. You really can't get it on the drivers side.
Your best bet will be to have all the upholstery steam cleaned (if it's cloth), the headliner steam cleaned (or reupholstered), and thoroughly wipe down any plastic interior surfaces. Cigarette odor is notoriously tough to remove from a car, especially if it's been smoked in for years.