How do I eliminate cigarette smoking odor from my car?

Hi Florence, leave the windows open as much as possible. Place charcoal briquettes in soft cotton bags in various areas such as under the seats, etc. Wipe as much of the interior down with hot soapy water. Shampoo the carpets & cloth upholstered areas well with vinegar added to the shampoo mixture. It's nearly impossible to get the smell out if it's a car that has been smoked in for years!

Florence...I would try one of the deodorizers that hang from mirror or knob/button if you have. Just find a good scent. I like the clean linen.

I have a gel air freshener that miight help https://www.yourbeautyblog.com/2018/11/diy-gel-air-freshener-with-essential.html

Also crumble up newspapers and put them under the seats.

My aunt used to smoke in my car. The best thing I've found is Ozium https://amzn.to/2SpSoXM

Vacuum and shampoo the carpets. Upholstery cleaner for the seats. Don't forget all the plastic and vinyl...dashboard, doors, console. Get everything in auto department or auto parts store.