No, there is no car mileage adjustment that is legal in any state of the nation. The reason is simple: car titling is based on current mileage, and if a dealer were allowed to rollback the mileage on an odometer, for example, you would not know that you were getting a vehicle with more miles on it than the odometer read. This is out and out fraud and attorney generals across the country come down on any dealership that tries to change mileage. About the only mileage that can be stated – and only once – is a new vehicle that is still on its Certificate of Origin, or the original build order. Once it has been registered, the CO is no longer valued, nor is its mileage.
For more info, see How The Odometer Reading Works