If it helps, I picked up a SSB coupe in a private sale last weekend. 17,500 miles with Nav and excellent condition but in need of rear tires for $15,800 in a private sale. That was in CT. So, similar cars / mileage but different parts of the country. Still, $17,800 doesn't seem horrible for a dealer price. And as for the Nav option, I wouldn't make that part of the decision to buy or the pricing. The Nav system on these cars is ummm.....unique and eccentric.