Instrument Panel problems of the 2008 Mini Cooper

My 2008 Mini Cooper speedometer is off by approximately 6 miles an hour. So that if I am actually driving at 50 mph the speedometer will show 56 mph. Additionally, if I drive 100 miles, the odometer will actually show as if I drove 106 miles. This is both a safety issue as the instrumentation is wrong, as well as a fraud issue as the car loses value because of the perceived additional miles driven and would be out of warranty sooner because of the perceived mileage amount. Also, if this were a lease and I went over the amount allotted by said lease, Mini would penalize the drive per the mileage. BMW/Mini has told me that they are aware of the issue and say its not a problem as they give alot of leeway for the accuracy of the speedometer.