Mileage verification

[CitySlicker]

I viewed a car recently and the condition didn't suit the mileage. I know it's quite rife to clock cars, especially out here in the Middle East, does anyone know if mileage can be verified through the gearbox like Porsche or Ferrari? Or maybe there's another method?

Car in question is a sls so engine is the M159 and as far as I know the gearbox is the same unit in the Ferrari 458