I came across an 08 GT500 for sale with 21k miles for $37.5k, and I've done some researching to find a good idea of what the true market value is of the car and have come up with some wildly different numbers. Kelly blue book has it at $39.9k while edmunds says $31k. I've searched locally for more cars like it and a lot of places are still asking over $45k+ for GT500s for sale of the same year. Its a car I am mildly interested in, and I will say I am more interested at the edmunds value rather than the kelly blue book value. What are the rest of you finding is a fair value for these cars?