In negotiations, the insurance company may want to show that you were more at fault than you claim in order to reduce your payment. To counter them, it's important to start negotiations with as much information as possible. Police reports, photos, and witness testimony can be solid evidence to help prove your innocence in an accident. While every insurer is different, most will contact local dealers and outside companies to see how much a car similar to yours sells in their area.
It's not known if they examine all vehicles or on a small scale, so it's best to do your own research. In addition to using the Internet as a resource for collecting sales data, contact local dealers that sell a make and model similar to those of your vehicle.