Photos and cars are real ( wow..

) but the story is indeed a well known fake.
Excerpt from
http://www.hoax-slayer.com/barn-cars.shtml"While the photographs are genuine, the text in the email explaining their origin is untrue. There was no retired New Yorker who came across an incredible, and totally unexpected, windfall when he broke open the welded doors of an old barn on his newly acquired Portuguese property. Instead, there is a more mundane, but much more believable explanation.
Journalist Tom Cotter researched the story and finally identified the photographer as Manuel Menezes Morais. Morais was contracted to take photographs of the cars by their owner. Due to the wishes of the owner, Morais was unable to reveal exact details of the barn's location or the owner's name, but he did give Tom Cotter some general information about the origin of the vehicle collection. In an article about the cars for Sports Car Market Magazine, Tom Cotter notes:
The owner of the cars was a car dealer in the 1970s and 1980s, and decided to save the more interesting cars that came through his doors. When the barn was full, he padlocked and "soldered" the doors shut. (Perhaps welding was too permanent.)
Web sites varied on the number of cars: 58, 100, and 180 were speculated. According to Morais, there are 180 cars in the barn......"