Kelly Blue Question
 

Had a friend in the business tell me if your car has a car fax history.
such as a fender bender you can deduct 10% from the listed trade in value.

does that seem about right..........

I would think it would depend entirely on the dealer and your negotiating skills

I find that not many dealers use Kelley values... they typically use NADA. I've never had an issue with them discounting due to carfax histories (infact I don't think I've ever had one check) but they do look at modifications and things of that nature. I had a pretty new car once that a dealer really robbed me on because I had modded it (in a bad fashion may I add) too heavily for them to sell it on the lot.

If the dealer gives you a hard time about a carfax I would take it somewhere else.