I had a friend trying to sell his 68 Road Runner for $14k years ago, he was contacted by a guy who said his 'client' was in South Africa and how people there love American muscle cars. A 'representative' sent a BofA cashier's check to him for $18k, with instructions to cash the check and use the remainder to ship the car via freight container, and to put the remainder in the glove box. He even called the bank and they said the cashier's check was legit, and so did his own bank, but instead of depositing the check into his account, he went to a BofA and wanted the cash. Fortunately, he was still skeptical because when he tried to cash it the teller told him that the number on the cashier's check had already been issued and that it was no good. Basically, it was a very, very good forgery.
My rule of thumb: anything that sounds too good to be true usually is, and scammers will do anything to get your car, your parts or your money.