51 I was getting tired of the aftermarket car scents that dangle from your rear view mirror. Besides, short of going to an automotive store, I was never able to find a coffee scented car freshner so I decided to make my own. Total cost= around 3 dollars. Here are the supplies you will need. Coffee beans, a small jar to hold the beans (preferably with an aluminum lid), a fork (I used a hammer and a small pick for making the holes in the lid). [via] Link.