Actually, I think that this post was the most sensible course of action if you want to increase your chances of getting more cash back. It really depends on your insurance company, and I have had dealings with a State Farm insurance adjuster as a consultant on several cases.

State Farm generally uses a third-party agency that will check several sources to find the average price of similar used vehicles in your area. They WILL, however, adjust their price or do more research on the case if you can show them a list of cars similar to yours in the area that are listed for more than they are offering you. The third party agence sometimes is way off! I recently reviewed a case that was off by over $1500, and the claiment received the greater amount. It will not hurt anything to submit your case if you can back it up (unless your insurance company is not as accomodating as State Farm, that is).