Im buying a 4.6 with nav for 39,200. I have a 2005 Infiniti g35 coupe, sport package, 19", and moonroof, with 36,800 miles. The NADA value is about 20k and KBB aroun 17,500. I took it in today to get appraised there ( after a week of trying to negotiate the value), and after they were done...