The Daily Star Sunday says the madcap Man City star turned up at a showroom in Wilmslow, Cheshire, last month and took a shine to a red Ferrari Modena.
But the deal fell through when the Italian was unable to answer some private security questions to sanction the funds.
A source revealed: "Mario loves fast cars and had signed some paperwork.
"But the sales staff couldn't believe it when he was put through to banking authorisation and couldn't remember some essential details!
"He was a bit annoyed by it but not as much as the sales staff who would have picked up a generous commission from the sale.
"Mario said he would come back for the Ferrari but he never bothered!"