[Scott R]

When I was a wrench for Cadillac I would see heavily smoked in cars come in all the time, the detailers would try everything, and you could still tell. Short of pulling all of the duct work out and scrubbing it, it will be there forever. You then of course also have to deal with the gauge faces, they will varnish over in time and have to be dissembled. You then still have to either toss the upholstery or attempt to clean it, best thing to do is to never buy a car that's been smoked in.