[denverpete]

Kelly Blue Book isn't going to be a very good representation of what the vehicle is really worth. The price of this vehicle is extremely linked to its condition.

Are those 17,000 miles for the life of the vehicle?
Is this "standard" or "Tiptronic"?
What's the condition of the vehicle? (curb rash on wheels, door dings, paint swirls, chips, interior parts not worn, etc).
What condition is the top in? (wear marks, fading, condition of plastic window)
How much tire is left? (these aren't cheap)
Does it come with an owner's manual and 2 keys?
Does the owner's manual show that all necessary work has been performed? (stamps)
Does it come with the Radio Code?
Is the original tool kit there and complete?
Has it ever had an RMS failure? What about a MAF failure?
Has it been "modded" in anyway? (wheels, tires, performance chip, exhaust, short shifter, deambered, etc)

Even if all of these turn out good and there is at least a 1 year warranty on the engine - I still wouldn't pay over $18,500 for it (extra $500 for the hard top).