I went with #1 son yesterday to look at cars for sale. The one he is most interested in has a faint odor of cigarette smell in it. I mentioned it to the used car manager and he acknowledged they were aware of it and would "ionize" the car during the detailing process if we bought it. How realistically can I except the smell, however slight, to go away.
This is going to be tough to fully dissipate, but depending on the strength, I would say it's possible. I've managed to get rid of the smell of cigarettes in one car I've worked on, but it was a very, VERY lengthy process that took days to fully purge.
Here is what I did:
1. Pull everything out of the car... I mean, undoing seats from the tracks, cushions, spare tire from trunk area, trunk floor deck, and if it's really bad you may want to remove the carpet all together and headliner. You need to pull the soft surfaces out of the car to really work on them.
2. With everything out, scrub all the surfaces like crazy and don't miss any of the cracks or crevices. Open the center console, glove box, hidden pockets in the seats or door... go crazy looking for any hidden areas. On the carpet and seats (if cloth) it's time to scrub those and do a hot water extraction as well. Use a shampoo, APC dilution, or any other safe cleaner to get the surfaces as clean as possible. You want to penetrate as deeply as possible to get as much gunk out as you can. If it's an option, leave the seats, floor mats, and carpet outside in the sun to fully dry.
3. If possible clean out the air vents but putting a dust/scrub attachment on the end of a vacuum and reaching in.
4. Change the in cabin air filter, and before installing the new one, spray with ozium (This is what I have used and have had good results). With the new filter installed, spray the fresh air intake on the car with ozium and let it suck in fresh air for 10-15 minutes to help get into all the vents in the system.
Once I did all those steps and the soft surfaces were cleaned thoroughly I had to go back to spray the ozium 2 more times in the vents with all the insides of the cars put back in.
That seemed to do the trick! Hopefully this helps...