There are plenty of carpet and upholstery cleaners you can purchase directly from your local auto parts store. They’re affordable, effective, and can usually help you get rid of any bad odors in your car’s seats or carpets.
Carpet cleaning products are not perfect by any means, but if your car has developed some more mild odors, they can definitely help cut them down.
To use them, you just have to spray the product on the affected area (or on all of the carpets and seats), and then work the product in. Once it’s been worked in, you just use a towel to dry the area and let it sit until it air dries.