Tree Fender

First of all, rear ending a car is aalyws going to be to your detriment. However, to answer your question about disputing the amount perhaps I can assist you. Always try to get a couple of estimates of the damage to the other person's car. You will find that the estimates vary. I keep a camera in my car to take pictures for just this reason. Presuming you didn't do that then you need to request a copy of the estimate done by the insurance companies adjuster and at this point you may want to get your own adjuster to review those estimates. So pictures before car is repaired, other estimates, review insurance adjuster's damage and finally your own adjuster would be the step I would go.Good Luck