Is money taken as compensation for car scratches from the person who caused them, as determined by a police officer, considered unlawful (haram)? And does the ruling change depending on whether the perpetrator intended their action or not?

If the perpetrator admits to their offense, they are liable for the value of what they destroyed. If they agree to pay a specific amount as compensation for what they damaged, then there is no harm for you in taking it and benefiting from it, because compensation is based on equivalence or on what the two parties agree upon. "Reconciliation is best," and "Reconciliation is permissible among Muslims, except for a reconciliation that makes lawful what is unlawful, or makes unlawful what is lawful." As for the intent behind the act, it affects the sinfulness, but not the guarantee of compensation. The unintentional wrongdoer does not sin but is liable for what they destroyed. However, if there was coercion from the police, then it is not permissible to take an amount exceeding the value of the damage.