Legally, you can’t get any loan until you’re 18, even if your parents are cosigners, so a car loan
won’t be an option to help you build credit for at least a couple more years. One option you do have in the meantime to build your credit would be to get added to a parent’s credit card as an authorized user. Just keep in mind that in order for this to benefit you, whoever is deemed responsible for the card will need to make consistent on-time payments.
If you want to take a step toward adulthood, you could consider asking your parents to pay cash for a car. Then you can start paying them back every month with a small interest rate. This will help you build good habits in the future and prepare you for loan payments as an adult so you can get a head start on strengthening your credit.
MORE: How to build your credit score without applying for a credit card