Mileage Correction on Continental, can it be detected?

[puss]

I'm appealing to anyone who might have a clue about this. I'm planning to buy a Continental GTC, probably around 2008 is the newest I can stretch to, and I'm wondering if there's any way of detecting if a car has had its mileage 'corrected' (fiddled) in its past? It's always struck me as too much of a coincidence that any car being advertised for sale, especially by smaller traders, seems to have a mileage just below a psychologically significant figure, say 39k, 49k, etc, Bentleys included so I suspect that huge numbers of cars have had this done in their lives.
My intention is to take out a Bentley warranty on a car if I buy it privately so obviously if a Bentley dealership can detect this sort of activity when making a claim they'd no doubt reject the claim. Besides, I'd rather buy a genuine untampered car.
I appreciate that major discrepancies would show up when looking through service and MOT records so I suspect this sort of thing is usually done to knock off a few thousand rather than tens of thousands but I'd like to know if I take it to Bentley for a pre-purchase check if they can detect a 'correction'?

[puss]

Byteme said:

The simplest method on a 2008 car is to check the MOT history on the VOSA website which records the mileage at all previous MOT tests. To do this you will need the registration document reference number which any honest seller should be happy to provide you with.

Mileages can be altered but a dealer should be able to compare what is shown on the display against data stored.

One reason you will find many of these cars with rounded off mileages is that they are advertised by agents hoping to sell on a commission basis while the car is still being used by the owner.

Thanks for all replies so far.
By "data stored" in para 2 above do you mean in the car's ecu or at the VOSA site? Thanks