If you go to a car auction and buy a car, you buy sold as seen on the basis that you are not paying the mark up that dealers and forecourts charge to give you the aftersale service i.e. when the engine needs replacing the next day a dealer will repair that for you. If you choose to buy a car from ebay then surely it has to be the buyers responsibility to ensure they are buying what they want. For all the people who complain about bad purchases on ebay there is obviously hundreds of thousands who are happy. I myself have purchased lots of items on ebay (at least 3 or 4 cars included) and have been more than happy.
To talk only about the people selling dodgy vehicles as being greedy is wrong because the buyers are the greedy ones also trying to get a cheap car but not having the experience or knowledge to spot a buy that will need more money spending on it to make it roadworthy. Should they not stick to the forecourts when purchasing such important items such as family cars? They may well pay a premium for this choice but at least they can have some piece of mind if only for the first three months of ownership, by which time any faults that where around before they made the purchase could be sorted. I don't wish to sound unsympathetic to people who have made bad purchases but ebay is no different to any other auction when it comes to a refund. The onus is on the purchaser to go over the vehicle in detail, if you don't, then you should accept the responsibility yourself.