How do we get the appropriate value for our car after it was hit by a distracted driver?

Our car was parked and a distracted driver hit the car parked behind our car, pushing that car in to our car. Our car was assessed by the drivers insurance company, we were told it was not worth repairing, and they offered us a ridiculously low amount for the vehicle ($513.08). The vehicle is a 2005, and we had just replaced tires and exhaust for that amount alone. The event happened almost a month ago, and we are still waiting for a decent settlement. We are also paying storage fees, but the insurance company says they only want to pay 3 days. We did not hear from the insurance company until 13 days after the accident. We would like to know what to do to get fair value for our car, and, if possible, reimbursement for the storage fees and towing to have it removed from the place it is stored. Thank you.