ive been here before. figure out what you think is fair price for your car, back it up with reciepts. ask for a bit more than you want. you do not have to accept the insurances offer and they have to keep paying for a rental car until they settle. threaten that your going to get a lawyer. i got paid for my car plus most off my mods, wheels and all of the audio gear i had. i didnt have a repiept for everything. i was dealing with a small insurance company and my insurance company(statefarm) even got on their case to pay me what i want.