Man its gonna be tough. To be honest with you I dont know how you can do it now that its wrecked. I got my Truck appraised as soon as I got it since I asked the Insurance agent how much I would get if wrecked..they told me BOOK VALUE ..no more. UNLESS.....I got a certified appraisal. Which I did. this was for $30k before the wheels/tires/engine etc. Every reciept for this afterwards will count towards the value of it if anything ever happens. You have to make sure and ask questions ahead of time. If you like I can find a copy of my appraisal if it will help to balance out the lowball offer they gave you.