What is the name of your state (only U.S. law)? My son's stepson is 20 years old and lives at home (NJ) with his mom and stepdad. He chooses not to have auto insurance because he can't afford it, he dropped it after he registered his car. If he injures someone in an accident can the injured party go after his mom and stepdad? My son seems to think that since his stepson is over 18, he would be completely responsible.