Its fairly common from my experience - the glut of low price/low mileage lease deals on Golf R's roughly 3 years ago wont have helped issues either. As far as I can tell it is becoming common practice in some circles to give certain performance cars a haircut very close to their first MOT Gearbox, ECU and ODO counters are all altered electronically for a price. Worn seats, brakes, steering wheels, non og tyres and heavily chipped paint are obvious indicators Always buy on condition rather than mileage! I am sure the dealers could do more to prevent it happening but its probably not a concern of theirs unless the warranties start to cost them dear on replacement components
When I first worked at a certain Rolls dealer the boss showed me how to clock Silver Shadows. I always felt sorry for his customers.