The 1981 Ford Escort Ghia Saloon was given to the late Princess of Wales by her husband-to-be in May 1981, two months before the Royal Wedding.
The 40-year-old car disappeared from public view for over 20 years - having been privately owned by a big fan of Princess Diana's, who kept the car's Royal history a secret even from her friends.
But today (Tues), the vehicle appeared as part of the Royal Auction at Reeman Dansie auction house in Colchester, Essex.
And it exceeded its guide price of £30,000-£40,000, when one lucky bidder snapped it up early in the day for £47,000.
The vehicle remains in amazingly original condition, with its original paint and upholstery, and 83,000 miles on the clock.
The clean, white car even bears the same registration plate it had when Diana was driving it - WEV 297W.
The Ford was Princess Diana's personal transport in the early part of her relationship with the Prince of Wales.
She was often seen driving it, and even watched the Prince playing polo whilst sat inside the car.
It comes complete with a silver frog mascot on the bonnet - a copy of a gift from Diana's sister, Lady Sarah Spencer, to remind her of the fairytale of a girl whose kiss turns a frog into a prince.
One of Princess Diana's other iconic cars, her Audi convertible, sold last year for £58,000.