Thank you for your letter; it took courage for you to write it and admit what you did. Hopefully it won't only warn others (especially those your age), but it will also make you a different person -- with God's help.
I don't use that last phrase lightly, because God certainly did help and protect you and your passengers from serious harm. Tragically, this doesn't always happen, as the headlines proclaim far too often. When we're young, we don't think about what might happen because of our thoughtless behavior; we think we're invulnerable. But it isn't true, and it only takes one mistake to destroy someone's life or future -- no matter how young or old we are. This is especially true when we get behind the steering wheel. Alcohol, drugs, texting while driving, or simply "showing off" can end up in tragedy and heartache.
The real question, however, is this: What does God want to teach you through this? Yes, He wants to teach you to be a better driver. But more than that, He wants you to turn to Him and put Jesus Christ at the center of your life. Commit your life to Him today.
Then ask God to make you into the person He wants you to be -- not just now, but for the rest of your life. God loves you, and Jesus Christ gave His life for you. Let the Psalmist's prayer become yours: "Send forth your light and your truth, let them guide me" (Psalm 43:3).