Sixteen year olds can't own cars or anything else because they can't sign a legally binding contract. Legally cars and other things with a title document have to be in their parents name, and legally even if a teenager has a job and buys a car with the money they earn, their parents can take it away or sell it because legally it doesn't belong to the teenager. You have to be of legal age to sign a legally binding contract. That's been the law for decades.