my mom had a will but she died and its not been found. the only property she owned was her car. what are my legal obligations?

Although my mom had a will ( she named me as co-executor years ago and i signed that ppwk). She died and it was never found. I personally cleaned out her entire house and have gone through all of her files. THere was no safety deposit box at her bank and her attorney says he didnt write it. The only property she had is a car. i'd like to give it to my brother but what are my legal obiligations?