"One of two things will happen," said owner Brandon Tudor, an Oswego salesman and father of three. "It will go for an astronomical amount or I'll get nothing."
Tudor, 29, said he was driving along U.S. Highway 30 near Big Rock Wednesday when bird poop hit the windshield of his 1996 Cadillac Seville, the Chicago Sun-Times reported.
He said he immediately saw a resemblance to the pop icon and it became more obvious "after it hardened."
"Everybody loves it," Tudor said. "There's not one person who's seen it that doesn't agree it looks like Michael Jackson."
The minimum starting bid for the windshield is set at $500 on eBay. Until the auction closes, Tudor is keeping the bird poop image covered in plastic to protect it from washing away and parking his car in a garage.