The body of David Lee Niles went missing on October 11, 2006.
Since that day no traces of the elderly man, who was suffering from cancer, have been found.
Workmen made the grisly discovery when they arrived at the lake, in Michigan, US, to install Christmas lights on a nearby pine tree, the Kent County Sheriff Department told media.
Later pictures revealed the car had been visible on Google Maps.
Byron Houseman, one of the workers, said: "All of a sudden, it's like, 'Whoa, there's a car out there.'
“No one could ever see it. It was murky and things moved around."
Soon after finding Mr Niles' body police contacted his family, who said the discovery will finally allow everyone to move on.
Mr Niles' son-in-law Scott Hathaway told local media:"For us today, it's a closure of a long search."
"Why God waited nine years, I have no idea, but we're happy. It's good to have him home."
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