Insurance companies always make a lo-ball offer initially to save themselves money. I don't think they really expect you to take it, But if so, sweet deal for them.
Car value. If you did not over pay for the vehicle and and show them receipts, they should upward revise their offer. If the car is totalled, and they value the car less than book, then challenge them to find you one in similar condition to replace yours. You don't have to accept any of their offers, technically. They will certainly try to wear you down and hope you get desperate for some kind of pay out...any payout.
If you're asking for an amount below what small claims court can handle, take the in. co. to court for a reasonable settlement. This is where those receipts, plus any improvements, taxes, or fees, you made toward the vehicle will be truly considered by the judge. Don't forget to document lost wages and any doctor bills resulting from the accident.
Usually such documentation will make the ins company see reason and offer fair settlement. Otherwise, it's lawyer time. And, that's another expense to add to the settlement.
Remember, is is easy for you to get emotional, and ins co.s will try to take advantage of that, too. The companies are emotionless. You have to be a colder hearted bastard than they are. But, don't lose your temper, curse, or present anything other than a reasonable and fair persona, who simply wants proper restitution.
Best of luck,