Hello! This thing, it really sounds a headache. Because your question is not well described, so as far as I know and know, let me say:

Where was the rear car and what road had a traffic accident? If the rear car is driving on the highway (or highway), the front car will fall off, and if it hits the front car because it can't dodge. The rear car was treated as a rear-end collision because there was no safe distance.

if the rear vehicle is driving at high speed, the front vehicle will drop something. In order to avoid the front car, the rear car hit the isolation belt or hit the guardrail on the expressway. First of all, the front car should not be allowed to leave, and the police or insurance company should be called immediately. The front car is the main responsibility of this traffic accident.

if the rear vehicle is driving at high speed, the front vehicle will drop something. In order to avoid the front car, the rear car hit the isolation belt or hit the guardrail on the expressway. Running ahead, we can't find the vehicle that caused the accident, so the third party can only be the highway management department in the case of compensation in the future.

I'm also "hearsay". Maybe it's wrong! Actually, the liability accident book issued by the local transportation department shall prevail. If you are not satisfied, you can bring a lawsuit in court!