Second, the other side may be suspected of causing trouble by stopping the car. You should pay attention to the alarm and keep the photos or monitoring and video materials at that time.
Three, the other party forged a signed contract, which may be suspected of fraud. If it is indeed a forged signature, you can apply to the court for handwriting identification.
I suggest you handle this matter calmly and settle it through consultation on the basis of finding out the facts. However, it is not excluded to solve it through the court. When it is time to call the police, we must resolutely call the police and keep the evidence.