If your parents caused through the use of a registered car in your name to have parking tickets that you were not aware of where the result is that your credit now has blemishes, you can sue your parents for the unpaid parking tickets and your credit damage.You might be able to establish with reasonable certainty your damages for the unpaid tickets. However, proving credit damage is quite complicated and typically requires the retention of an expert witness in the area of credit damage.I suggest that you simply have a face to face meeting with your parents before filing a lawsuit to try and resolve the difficult situation you have been placed.