This sort of thing probably varies from state to state, and insurance company to insurance company. Still chances are very good that you can bank on one thing: the insurance company will try to pay as little as they possibly can.
Point #2, the number they are giving you now might not be the final number. I remember once getting a settlement higher than what the company wanted to give me because I argued, pointing to plusses on the car that made it worth more than what they thought.
In your case, the low miles are a big plus. 69K is typical for a car that's maybe 5 years old, not more than 15 years old. I did a really fast Internet check, and found that
www.nadaguides.com lists a Buick Roadmaster worth only $2,500 retail, clean condition. BUT if it has 69K miles, they add ANOTHER $600 to the value. Total value: over $3,000. I'd encourage you to fully research your specific model (nadaguides.com lists 2 Roadmasters), miles, etc. Also look at local conditions. You are looking for information that will allow you to claim the car is worth far, far more than what the insurance company says. Although, they might not accept some information. (The last time I did this, the insurance company told me bluntly to avoid Kelly Blue Book prices. They were--at least then, and in my market--too high. Your market may vary.)
Finally, if the company is unreasonable, there is always the threat of reporting them to whoever regulates insurance companies in your state.
