What is the best way to fight an auto insurance company if you are unhappy with the settlement they offer?

Is it a property damage settlement, or are there personal injuries, wage loss and other damages? If it's property damage only, you should be aware that a settlement you consider "fair" may simply be the value of your car. Stuff like recent new tires or sentimental value or worse, that you're upside down on your loan - those aren't considered. Simply put, they don't owe you what you owe on the car. They just owe you what the car is worth. If you have injuries and wage loss and feel they're offering you a low settlement, the best way to fight an insurance company is with a lawyer. Yes, there's a fee. However, you will not get a fair settlement on your own. Even pursuing the lower cost option of arbitration is still risky without a lawyer. You can be sure the insurance company has in-house lawyers to represent its interests, even in arbitration.