Regardless of the warner's name, if your parents are expecting to receive money from a stranger, for a vehicle the stranger has never seen in person, it is almost certainly a fraudulent check scam.
Typically a scammer will send a check for more than the cost of the vehicle. He will then claim that the "extra" money is to be sent to his "shipper" or some other 3rd party. In some cases, he will claim that he accidentally overpaid, or (more rarely) that an emergency came up and he needs the money back. In any of these cases, his goal is going to be to get your parents to deposit the check and almost immediately withdraw the money to send via wire transfer or some other untraceable means (like a prepaid card.) The scammer's goal is to collect that money. He is counting on the fact that many people believe (wrongly) that a check has cleared if the bank makes the funds available. In reality, the check can still be found to be fraudulent after the money has been released (even weeks to months later), and the person who deposited the check will ultimately be required to pay the entire amount of the check back to the bank, plus fees for depositing a fraudulent check in the first place. By the time your parents realize that they have been had, the scammer and the cash will be gone, with no trail since he is using a fake or stolen name and fake information.
Just because the person isn't necessarily from our site doesn't mean that the warning itself is invalid. Sometimes people who fell for a job scam will discover the truth about the checks that they have printed and/or sent, and they will try to warn the recipients on their own. They might reference our site because it is where they learned the truth. But if they contacted your parents, and your parents are in fact dealing with a buyer sending a check, it's pretty likely that the information is accurate.