I was speaking to a reputable mechanic who buys a few cars and services them before selling them. He explained to me how difficult it is to be sure of payment citing this example. Agreed a price with a "purchaser". "Purchaser" asked how he wanted payment and mechanic stated cash. Both went to a local bank and mechanic stayed at the back of the bank reception area while "purchaser" goes up to the cashier. "Purchaser" meets mechanic at the back of reception area in bank and money counted out and keys and documentation exchanged. Mechanic goes up the cashier to lodge proceeds only to find that it is all forged. Cashier is able to tell mechanic that the "purchaser" just changed a €50 note into smaller denominations. Car located about 10 days later crashed.