i just went through this. Had my car totaled about a month ago. What my insurance company did was.
They went out and found 10 cars in my local area that where close to the mileage and condition as my car was before the accident ( from dealerships, autotrader, whereever) Then they took the average price of those ten cars and that is what i got. The number was fair but of course lower than i wanted. If i where you i would look into doing your own research like this. Find cars in your area that are for sale with similiar features and mileage and that should give you a good idea of what the insurance company is going to offer. If they low ball you, get a lawyer involved. Also i would seriously consider looking into a doctor. I walked away from my accident and the next day i was hurting pretty bad but didn't think anyways was wrong. I was semi-forced to go see a doctor. Now i have a herniated/Torn disk in my back and also a buldging disk.
Get checked even if it doesn't hurt, don't mess with back injurys they can really mess you up.