Remove all trash, ash, and cigarette butts
Take out floor mats and clean them separately
Vacuum seats, carpets, trunk, and crevices thoroughly
Wipe all hard surfaces with an interior cleaner
Clean windows, mirrors, and dashboard surfaces
Replace the cabin air filter
Sprinkle baking soda on carpets and upholstery, let sit, then vacuum
Use activated charcoal or odor absorbers inside the car
Steam clean upholstery and carpets
Shampoo fabric seats and floor carpets
Clean leather seats with a leather-safe cleaner
Clean the headliner gently with a suitable cleaner
Run the air conditioner and heater with fresh air intake
Use an ozone treatment if needed
Leave the car windows open in a safe, dry place
Repeat cleaning steps until the odor is gone