Remove all trash, ash, and cigarette butts
Vacuum seats, carpets, floor mats, trunk, and crevices
Wash or replace cabin air filter
Clean hard surfaces with an interior cleaner
Shampoo fabric seats and carpets
Wipe down windows, headliner, door panels, and steering wheel
Sprinkle baking soda on carpets and seats, then vacuum after several hours
Place activated charcoal bags in the car
Use an ozone treatment if needed
Run the fan with fresh air and replace air fresheners as needed
Clean or replace seat covers and floor mats
Repeat cleaning until the odor is gone