As a smoker, whose vehicles never smell like smoke. And I have detailed other smokers vehicles with amazing results after they had quit. The trick for reversing what problem you have( smoker that did it with windows up all the time) The ac evap and heater core keep alot of that stuff held on to the fins, You can pull the blower motor out, spray down the evap with coil cleaner, and second thing I would do while I was there, Pull the vents out of the dash, get one of those bendy pickup tools and grab a microfiber on it, get the microfiber pretty damp with a good citrius based cleaner go as far down the vent tubes as you can and clean it out, there is a ton of buildup on the walls of those. DOWNRIGHT disgusting when you do it. You have to do a different approach to the rear, but somewhat the same. After you are done, put ac on high super cold setting to condensate the evap real good to wash the junk out. It will smell a bit citriusy for a while but It should pretty dang stellar, my buddies always say, damn I would think this was a new un smoked in vehicle.
Hopefully this can get that last 10% out.