If a car is totaled and the policy did not make adequate payment, what could be the reason?

Majority of car insurance policies would pay only the actual cash value or ACV of a car that had been totaled in accident. The ACV is calculated based on the market value of the car immediately prior to the accident. Normally, the insurers would be required to use a reasonable and fair method to arrive at the market value of the car before the occurrence of the accident. However, the person claiming the payment after the accident would be able to negotiate with the insurer if there is a feeling that the payment had not been adequate. For this, that person would be required to prove that the actual market value of the car had been higher than the assessment by the insurer.