All perfect praise be to The Lord of The Worlds, and may His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
The compensation to be received by the owner of the damaged car from the insurance company is a debt on that company, or on the party responsible for the accident. Moreover, selling the traffic accident sketch is prohibited even by agreement between the owner and the buyer because of the following reasons:
First: Transference of a debt for a sum is incurring usury(Riba) because it is selling deferred money for advanced money, and it is a condition for the validity of this transaction that payment is made on the spot. Narrated Umar: "The Messenger of Allah (PBUH) as saying: Gold for gold is interest unless both hand over on the spot."{Agreed upon}.
Second: The sold item is unknown in terms of amount and value, and Islamic Sharia stipulates that it should be known.
Third: There is gambling and Gharar(uncertainty) since the buyer could make a profit or lose, and Sharia prohibits such transactions.
In conclusion, one who has sold the traffic accident sketch of his car in return for a certain amount of money should repent to Allah, The Almighty, and return that amount to the buyer, then collect the compensation from the insurance company. However, if he couldn`t return that money immediately, he remains liable for it until he pays it off. And Allah knows best.