Trade in value

I understand, I could of used Black Book to , wich update the value of cars daily, but I didn't, cause your site is the one that says it offers 2 grand over book value, that's why I decided to use your site to get the value of my car ... my question was why wasn't I offered 2 grand over book value when I put all the information in to the best of my knowledge, if something came back and I wasn't aware of it ,I would understand why the cars value was desperate... 2 things came back ,1 I was aware of, was the accident, and the other was the area in wich I live ... total of about $1,800. In discounts... but again nothing was said about the 2 grand over book value, and my question is why ???