Nicola Boycott shared a photo of the man - wearing just jeans and a t-shirt - face down on the windscreen of a Nissan Micra on Sunday morning, the day after England beat Ukraine 4-0 in Rome.
Her husband spotted the man at 9am "snoring his head" off.
Nicola even tried to wake him - to no avail.
She posted to Facebook: "Looks like someone had a good night.
"He’s snoring his head off on my neighbour's car and won’t wake up."
She added later: "Can we all share this please.
"He will walk into his house in a few hours - tell his Mrs that he slept ON a car all night and she 100% won’t believe him."
The post has received thousands of likes, comments and shares on Facebook.
Nicola told the YEP: "He was asleep on the neighbour's car when my husband went to the shop with our son at 8:30-9am ish.
"I tried to wake him - he was snoring his head off but must have been too comfy to get up.
"I put the post up because I knew that if my husband walked in one morning and told me that he had slept ON a car all night, then I would boot him back out the door with that ridiculous story - so I was just trying to back him up for when he got home."
It happened in Hartford, Cheshire, but has been shared in Facebook groups around the country, including Leedsplace.
One commenter on Leedsplace said: "Good job someone's got a photo because his wife/partner would never believe him
Another said: "Bless him - hope he’s not in too much trouble."
While a third person joked: "If I was the car owner id have moved the car backwards without starting it."
A fourth quipped: "Windscreen wipers might wake him up."
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