I got burned with the last car i bought a mercedes ml the transmission failed a few days after i bought it, it had been bodged just to last. Luckily i was able to remove and rebuild myself and it only cost me a few hundred in parts but if it was someone who is not good with spanners they would be looking at a very big repair bill. Im super cautious now. I could not sell a car to someone knowing there is a problem and lie to people. I wouldnt sleep at night. If i look at the past mot ect and what the seller says dont add up il walk away. At the same time if i spoke to a seller and they said its very good but the diff whines when warm that would not bother me in the slightest. Id be quite happy to pull the diff and rebuild it. Just hate devious lying scammers trying to palm off there rubbish for good money.