If you're bored sometime, call Ebay and ask about buying a car and claiming its "not authentic"
"Sir, I don't believe anyone would fake a car"
"But Ma'am, that argument doesn't hold water when a seller makes that argument"
I asked her if I sold a car and they claimed it not authentic how I would go about proving it was a real, authentic car.
She didn't have a good answer and further proved my point that you can buy anything on ebay, claim its not authentic...