HAVE you ever forgotten that you left a Ferrari in your shed 40 years ago?

No, me neither.

Yet remarkably someone did in Japan and now that Prancing Horse is worth a staggering £1.5million.

The legendary Daytona was capable of a staggering 174mph when it went on sale in 1969.

Around 1,200 standard Daytonas were built over a four-year period along with five competition cars for endurance racing.

They also commissioned just one street version of the Daytona with an aluminium body – and very few people are aware of its existence.

Filthy Ferrari Daytona found

Filthy Ferrari Daytona found

But it has now emerged after being left to gather dust and dirt in a lock-up in Japan.

The one-off Ferrari, once a bright red sports car, is a tired-looking classic in desperate need of an overhaul having been hidden since 1980 – but it is set to create a storm among collectors of unique cars.

Acclaimed Ferrari historian Marcel Massini flew out to Japan to inspect the car, where he confirmed its identity.

He said: “What a super scarce Daytona barn find, the only remaining aluminium-bodied production GTB/4, sold new to Luciano Conti, a close friend of Commendatore Enzo Ferrari.”

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The Daytona has now been shipped back to its birthplace, Maranello, Italy, where it will be sold by RM Sotheby’s as part of its Ferrari marque sale on September 9.

It is being sold without reserve, which means it could go for as little as one euro, but the auction house has given it an estimate of around £1.5 million (Euro 1.7m).

Whoever buys it is then left with a number of options – they can get it running but preserve its ‘barn find’ condition or restore it to concours condition.

Filthy Ferrari Daytona found

Filthy Ferrari Daytona found

And as a special, storied Ferrari it will be welcome at shows around the world.

RM Sotheby’s described the Ferrari as “a unique car that no other collector can claim ownership to”.

Under the bonnet of the Daytona is a 4.4-litre V12 engine which developed around 350bhp when it left the factory in 1969.

This would have given the sports car a 0-60mph time of 5.4 seconds and a top speed of 174mph – making it the world’s fastest road at at the time.

The first owner, Italian publisher Luciano Conti, took delivery of the car in June 1969 and kept it for one year before selling to its second keeper who re-sold it one month later to a Japanese owner in 1980.

It could do with a bit of Turtle Wax before they sell it though.