DeeDee - Parenting is something that you have to take time to do. Obviously when your in the car you're on the way to someplace so you may be rushed for time. If however, all you have time to do is threaten then your kids learn that there is nothing behind the threats. Take the time to pull the car over and take action and back up what ever you have threatened. A few times of taking action will let your kids know you mean business and will settle them down when you speak. Do this as often as it takes. Is it more important to always be on time or raise your children with boundaries and respect for you?