think our mileage was rolled back

[ProudUSNavyWife]

We bought our 2000 Ford Mustang GT with 38,949 miles on it on 3/30/2004.

We just came home from a trip to FL, by using mapquests directions it said it would be 1,077 miles (from our home to where we went in FL) When we got to FL our odometer said we had only gone 866 miles. On our way home today, we set up our odometer with the mile markers and it came out to be off by at least 7 miles (in a 30 mile span)

We also had to have the ring & pinion replaced at about 50,000 miles.

We did a car fax report on the car, and found out that it has had 3 other owners besides us.

The owner (a dealership) before us bought it at an auto auction. The car then sat on a dealer lot from 10/16/2002 with 14,088 miles until we bought it on 3/30/2004 with 38,949. It is very odd that the put on 24,861 miles in 17 months, and the mileage when we bought it (3/30/2004 with 38,949) going by the industry average it should have had about 60,000.

We now think that the mileage has been rolled back. Does anyone know is there is a way to tell if the mileage has been rolled back? And how I would go about finding out, and what to do if it has been.

The reason we think it has been is, having to over haul the rear at about 60,000 miles. When we bought the car (the tires) where not the factory tires (they had obviously been replaced once before) and we just bought new tires for the car. Also new brakes and rotors (the man who replaced our brakes and rotors said that they had been cut twice already) And also the mileage being off.

Any advice would be greatly appreciated. Thank you for reading