Police are investigating after a man said he left £80,000 on top of car then drove off.
Officers said the cash had vanished and they were treating the incident in Westcliff-on-Sea, Essex, as a theft.
They said the man told how he put the cash on top of the car early on Thursday November 18 but not realised what he had done until later.
"Police were contacted on Friday, November 19, by a man reporting that he had lost £80,000 in Prince Avenue, Westcliff," said a spokesman.
"He told police that he had accidentally left the money on the top of his car before driving off on the morning of Thursday, November 18 at 6.20am.
"He later realised what he had done. Essex Police has seized evidence found at the scene, to be checked for fingerprints."
He said officers had checked local CCTV cameras and enquiries were ongoing.