Yes it is possible to turn back the clock on the X5 and pretty much any car for that matter especially here in canada! But the l/kms could show pretty much any number depending on how many kms driven and how those kms were driven if you reset it and drive say, 50kms like your Michael Schumacher i have no doubt that the numbers you saw were acurate! Could be a sign of abusive driving by the stealer which i've caught them doing around here a few times! Like Ucrew said get the backlogs and look for anything out of place! Goodluck with the purchase and dont forget that there are plenty of fish(X5's) in the sea