Although you cannot trust online auctions entirely, auction websites such as eBay often provide tools to help users decide whether or not a seller is trustworthy. EBay lets prospective buyers view the seller's feedback from previous customers and shows small icons next to seller names to indicate if they're trustworthy.
Once on the individual page of a vehicle, check the box on the right to see rating of the seller. A yellow light bulb next to his name indicates that eBay recognizes the seller as a top-rated user. A glowing person icon means that the user has not used eBay for more than 30 days. A blue circle with two people icons in it is reason for suspicion as it indicates the user has changed his name in the last 30 days.